Some Revised Spells

[rferries]

Here are some buffed versions of existing spells. Be advised I'm still very new to 5e so while I may have identified some lacklustre spells, I may have overshot the fixes!

Arcane Weapon (Replaces Arcane Sword)
7th-level Evocation
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a miniature platinum sword with a grip and pommel of copper and zinc, worth 250 gp)
Duration: 1 minute

You create a floating, spectral weapon within range that lasts for the duration. The weapon traditionally takes the form of a greatsword, but it can take the form of any melee weapon you choose, or even that of a shield, spectral warrior, or some other form. The weapon's form does not affect its statistics. It occupies a 5-foot space and may share the space of a friendly creature.

When you cast the spell, you can make a melee spell attack against a creature within 10 feet of the weapon. On a hit, the target takes force damage equal to 4d8 + your spellcasting ability modifier.

Until the spell ends, you can use a bonus action on each of your turns to move the weapon up to 60 feet to a spot you can see and repeat this attack against the same target or a different one.

The weapon can take one reaction on every turn in combat, either to make opportunity attacks or to attempt to parry melee attacks against friendly creatures. The weapon may use its reaction to add your spellcasting ability modifier to the AC of a friendly creature against one melee attack that would hit that creature. To do so, you must be aware of the attacker and the weapon must be within 5 feet of the friendly creature.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the base damage increases by 1d8 for each slot level above 7th.

Classes: Bard, Sorcerer, Warlock, Wizard

Circle Of Death/Circle of Life
6th-level Necromancy
Casting Time: 1 action
Range: 150 feet
Components: V, S, M (the powder of a crushed black pearl worth at least 500 gp)
Duration: Instantaneous

A sphere of negative energy ripples out in a 60-foot-radius sphere from a point within range. Each non-undead creature in that area must make a Constitution saving throw. A target takes 11d8 necrotic damage on a failed save, or half as much damage on a successful one.

If you substitute the material component with the powder of a crushed white pearl worth at least 500 gp during the casting, the spell deals radiant damage instead and does not damage non-undead creatures.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d8 for each slot level above 6th.

Classes: Sorcerer, Warlock, Wizard

Enervation
4th-level Necromancy
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Concentration, up to 1 minute

Crackling black or ultraviolet bolts of energy reach out from you, striking creatures you can see within range to drain life from them. When you cast this spell and as an action on each of your turns, you may force a target to make a Dexterity saving throw. A target takes 4d8 necrotic damage on a failed save, or half as much damage on a successful one.

Whenever the spell deals damage to a target, you regain hit points equal to the amount of necrotic damage the target takes (gaining any excess as temporary hit points).

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th. When you cast this spell using a 9th-level spell slot, any damage dealt by this spell reduces the target's maximum hit points until they finish a long rest.

Classes: Sorcerer, Warlock, Wizard

Find Traps
2nd-level Divination
Casting Time: 1 action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 hour

You imbue a willing creature with a preternatural danger sense when it comes to artificial hazards. The target has advantage on Intelligence (Investigation) and Wisdom (Perception) checks made to detect and identify traps, on saving throws against traps, and on ability checks made using thieves' tools to disarm traps.

A trap, for the purpose of this spell, includes anything that would inflict a sudden or unexpected effect you consider harmful or undesirable, which was specifically intended as such by its creator. Thus, the spell would help the target sense an area affected by the alarm spell, a glyph of warding, or a mechanical pit trap, but it would not help reveal a natural weakness in the floor, an unstable ceiling, or a hidden sinkhole.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can target one additional creature for each slot level above 2nd.

Classes: Cleric, Druid, Ranger, Wizard

Flame Arrows
3rd-level Transmutation
Casting Time: 1 action
Range: Touch
Components: V, S
Duration: 1 hour

You touch a ranged weapon or an ammunition container (such as a quiver). When a target is hit by a ranged weapon attack using a piece of ammunition fired from that weapon or drawn from that container, the ammunition is magical and the target takes an extra 1d6 fire damage. The spell's magic ends on a piece of ammunition 1 round after it is fired from the weapon or withdrawn from the container.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can target one additional weapon or container for each slot level above 2nd.

Classes: Ranger, Sorcerer, Warlock, Wizard

Horrid Wilting
8th-level Necromancy
Casting Time: 1 action
Range: 150 feet
Components: V, S, M (a bit of sponge)
Duration: Instantaneous

You draw the moisture from every creature in a 30-foot cube centered on a point you choose within range. Each creature in that area must make a Constitution saving throw. Constructs and undead aren't affected, and plants and water elementals make this saving throw with disadvantage. A creature takes 13d8 necrotic damage on a failed save, or half as much damage on a successful one. A creature that fails its save gains one level of exhaustion.

Nonmagical plants in the area that aren't creatures, such as trees and shrubs, wither and die instantly. All fog and nonmagical liquids in the area vanish instantly, leaving only traces of dust.

You may exclude yourself and any number of friendly creatures from the spell's effects.

If you cast animate dead or create undead on the corpse of a creature killed by this spell, any undead you create are particularly desiccated in appearance and gain immunity to cold damage.

At Higher Levels. When you cast this spell using a spell slot of 9th level or higher, the damage increases to 15d8 and a creature that fails its save gains two levels of exhaustion.

Classes: Sorcerer, Warlock, Wizard

Instant Summons
6th-level Conjuration (Ritual)
Casting Time: 1 action
Range: Touch
Components: V, S, M (a sapphire worth 1,000 gp)
Duration: Instantaneous

You instantly call to hand any object weighing 10 pounds or less whose longest dimension is 6 feet or less. The spell brings you either a specific object (e.g. the broom you left at home) or any unattended object of its kind (e.g. a broom from an abandoned farm somewhere on a random plane). If you attempt to summon a nonspecific item worth 1 gp or more, the spell fails.

If the item rightfully belongs to another unwilling creature, is in the unlawful possession of another creature, or is currently under guard (whether by creatures, traps, or other defences), the spell does not bring you the item. Instead, you learn who the creature (if any) possessing the object is and roughly where the object is located at that moment.

Classes: Wizard

Stoneskin
4th-level Abjuration
Casting Time: 1 action
Range: Touch
Components: V, S, M (diamond dust worth 100 gp)
Duration: 1 hour

This spell turns the flesh of a willing creature you touch as hard as stone. Until the spell ends, the target has resistance to nonmagical bludgeoning, piercing, and slashing damage.

At Higher Levels. When you cast this spell using a spell slot of 9th level, the duration increases to 8 hours and the target has resistance to bludgeoning, piercing, and slashing damage.

Classes: Sorcerer, Warlock, Wizard

True Strike
1st-level Divination
Casting Time: 1 bonus action
Range: 30 feet
Components: V, S
Duration: Instantaneous

Choose a creature within range (including yourself). That creature has advantage on attack rolls until the end of its next turn.

Classes: Bard, Cleric, Paladin, Ranger, Sorcerer, Warlock, Wizard

Weird
9th-level Illusion
Casting Time: 1 action
Range: 30 feet
Components: V, S, M (a silver hand mirror worth at least 5,000 gp)
Duration: Concentration, up to 1 minute

You choose a non-deity creature within range and weave a nemesis for them from shadowstuff. The nemesis is a perfect copy of the creature (even including their non-artifact equipment) and attacks them relentlessly, acting immediately after you cast this spell. The nemesis cannot be charmed or frightened. It ignores all other creatures, and all damage it deals (whether from weapons or spells) is psychic damage. Creatures with truesight or true seeing have resistance to this damage and advantage on saves against the attacks of their nemesis.

When either the target or the nemesis is killed, the nemesis vanishes back into nothingness.

Classes: Bard, Sorcerer, Warlock, Wizard

Witch Bolt
1st-level Evocation
Casting Time: 1 action
Range: 30 feet
Components: V, S, M (a twig from a tree that has been struck by lightning)
Duration: Concentration, up to 1 minute

A beam of crackling, blue energy lances out toward a creature within range, forming a sustained arc of lightning between you and the target. Make a ranged spell attack against a target creature. On a hit, you establish a link to that target. On each of your turns for the duration, you may use your action to make a ranged spell attack against another creature to establish a link to that target as well.

When you cast this spell, and then as a bonus action on each of your turns until the spell ends, you may choose any number of linked targets within 30 feet of each other. Each chosen target takes 1d12 lightning damage, and any others are no longer linked.

A creature is no longer linked and cannot be targeted by this spell if it is outside the spell's range or if it has total cover from you.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the initial damage increases by 1d12 for each slot level above 1st.

Classes: Sorcerer, Warlock, Wizard


Glibness
4th-level Enchantment
Casting Time: 1 action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 hour

You imbue a willing creature with a great eloquence and personal charm. Until the spell ends, whenever they make a Charisma (Deception), Charisma (Intimidation), or Charisma (Persuasion) check, they can replace the number they roll with a 15.

Additionally, no matter what the target says, magic that would determine if they are telling the truth indicates that they are being truthful.

Classes: Bard, Sorcerer, Warlock, Wizard

[JNAProductions]

Just looked at True Strike, really, and it's absolutely insane.

Samurais get, three per long rest, advantage on all attacks for a turn and some THP.
At 10th level, they get a single use back when they roll Init and have none left.

Eldritch Knights, with this spell, get most of the same thing (just missing some minor THP) for a bonus action... At-will. And it can be used on others too.

[rferries]

Just looked at True Strike, really, and it's absolutely insane.

Samurais get, three per long rest, advantage on all attacks for a turn and some THP.
At 10th level, they get a single use back when they roll Init and have none left.

Eldritch Knights, with this spell, get most of the same thing (just missing some minor THP) for a bonus action... At-will. And it can be used on others too.

Ooops, I didn't account for subclasses. Bumped it up to 1st level.

[sandmote]

Bit tired, but most of these look fine at first glance (including true strike as a 1st level spell).

My one complaint is about glibness. For a fix this is far more niche than Skill Empowerment at one spell level lower. If you're applying it only to Deception and Persuasion checks, you can probably keep the "roll 15 minimum" aspect instead of slapping on a "advantage if it would do nothing" effect for the redundancy.

On top of that, the main point of glibness is actually that the classes able to learn it use charisma checks when using Counterspell or Dispel Magic against an effect higher level than the slot they've used to cast. The fact Counterspell can be Counterspelled probably limits it's use for Bards, but Warlocks don't have a strong combat option to spend their 8th level Mystic Arcanum on and this is a nice way to conserve slots in a pinch.

[rferries]

Bit tired, but most of these look fine at first glance (including true strike as a 1st level spell).

My one complaint is about glibness. For a fix this is far more niche than Skill Empowerment at one spell level lower. If you're applying it only to Deception and Persuasion checks, you can probably keep the "roll 15 minimum" aspect instead of slapping on a "advantage if it would do nothing" effect for the redundancy.

On top of that, the main point of glibness is actually that the classes able to learn it use charisma checks when using Counterspell or Dispel Magic against an effect higher level than the slot they've used to cast. The fact Counterspell can be Counterspelled probably limits it's use for Bards, but Warlocks don't have a strong combat option to spend their 8th level Mystic Arcanum on and this is a nice way to conserve slots in a pinch.

Oohhh thanks for the input! New to 5e so totally missed the glibness/counterspell interaction.For flavour reasons I think I'll limit it to the social interaction skills with the "15 minimum" mechanic.

[Yakk]

Here are some buffed versions of existing spells. Be advised I'm still very new to 5e so while I may have identified some lacklustre spells, I may have overshot the fixes!

Arcane Weapon (Replaces Arcane Sword)
7th-level Evocation
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a miniature platinum sword with a grip and pommel of copper and zinc, worth 250 gp)
Duration: 1 minute

You create a floating, spectral weapon within range that lasts for the duration. The weapon can take the form of any melee weapon you choose.

When you cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon. On a hit, the target takes force damage equal to 3d8 + your spellcasting ability modifier.

Until the spell ends, you can use a bonus action on each of your turns to move the sword up to 60 feet to a spot you can see and repeat this attack against the same target or a different one.

The weapon can take one reaction on every turn in combat, either to make opportunity attacks or to attempt to parry melee attacks against friendly creatures. The weapon may use its reaction to add your spellcasting ability modifier to the AC of a friendly creature against one melee attack that would hit that creature. To do so, you must be aware of the attacker and the weapon must be within 5 feet of the friendly creature.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the base damage increases by 1d8 for each slot level above 7th.

Classes: Bard, Sorcerer, Warlock, Wizard

I'd keep this as Arcane Sword. It is a replacement, renaming seems confusing.

You could also up its size so it has a 10' reach.

A 6th level spiritual weapon is a bonus action to cast, and deals 3d8+stat damage. So lower level and better action economy. The parry and OA is cute, but don't know if it is enough.


Circle Of Death/Circle of Life
6th-level Necromancy
Casting Time: 1 action
Range: 150 feet
Components: V, S, M (the powder of a crushed black pearl worth at least 500 gp)
Duration: Instantaneous

A sphere of negative energy ripples out in a 60-foot-radius sphere from a point within range. Each non-undead creature in that area must make a Constitution saving throw. A target takes 11d8 necrotic damage on a failed save, or half as much damage on a successful one.

If you substitute the material component with the powder of a crushed white pearl worth at least 500 gp during the casting, the spell deals radiant damage instead and does not damage non-undead creatures.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d8 for each slot level above 6th.
So you added 3d8 so it matches fireball.

(a) fireball is a high damage spell, don't balance against it.

(b) undead aren't immune to necrotic damage in 5e.

(c) do something more interesting than damage and undead/anti-undead friendly fireball with a bigger AOE.

What if it made a zone that lasted for 1 minute on top of the AOE damage? Like:

Duration 1 minute.

This creates a circle of death with a 60' radius within range. All movement within or above this zone requires an extra foot of movement for every foot of movement you move. The first time a creature is in the zone they take 15 necrotic damage. In addition, all creatures within the zone when it is created, who enter the zone, or who start their turn in the zone are poisoned for the duration of the spell, gain a level of exhaustion, and suffer 4d6 necrotic damage unless they make a constitution saving throw. Once you have failed this saving throw you do not have to make it again, but creatures who succeed at it have to repeat it each time they trigger it.

This is now a "fireball" that makes an area cursed, at least for a minute.


Classes: Sorcerer, Warlock, Wizard

Enervation
4th-level Necromancy
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Concentration, up to 1 minute

Crackling black or ultraviolet bolts of energy reach out from you, striking creatures you can see within range to drain life from them. When you cast this spell and as an action on each of your turns, you may force a target to make a Dexterity saving throw. A target takes 4d8 necrotic damage on a failed save, or half as much damage on a successful one.

Whenever the spell deals damage to a target, you regain hit points equal to half the amount of necrotic damage the target takes (gaining any excess as temporary hit points).

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th. When you cast this spell using a 9th-level spell slot, any damage dealt by this spell reduces the target's maximum hit points until they finish a long rest.
I like the "fire again", but I think the "once I hit you I can repeat it" is worthwhile.

Flame Arrows
3rd-level Transmutation
Casting Time: 1 action
Range: Touch
Components: V, S
Duration: 1 hour

You touch a ranged weapon or an ammunition container (such as a quiver). When a target is hit by a ranged weapon attack using a piece of ammunition fired from that weapon or drawn from that container, the ammunition is magical and the target takes an extra 1d6 fire damage. The spell's magic ends on a piece of ammunition 1 round after it is fired from the weapon or withdrawn from the container.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can target one additional weapon or container for each slot level above 2nd. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d6 for every two slot levels above 3rd.
No concentration? I get the old one was too weak, this one seems a bit too strong.

Also, shared quiver abuse.

Glibness
4th-level Enchantment
Casting Time: 1 action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 hour

You imbue a willing creature with a great eloquence and personal charm. Until the spell ends, whenever they make a Charisma (Deception), Charisma (Intimidation), or Charisma (Persuasion) check, they can replace the number they roll with a 15.

Additionally, no matter what the target says, magic that would determine if they are telling the truth indicates that they are being truthful.

Classes: Bard, Sorcerer, Warlock, Wizard
I'd take the original thanks.



Stoneskin
4th-level Abjuration
Casting Time: 1 action
Range: Touch
Components: V, S, M (diamond dust worth 100 gp)
Duration: 1 hour

This spell turns the flesh of a willing creature you touch as hard as stone. Until the spell ends, the target has resistance to nonmagical bludgeoning, piercing, and slashing damage.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the duration increases to 8 hours. If you cast this spell using a spell slot of 9th level, the target has resistance to bludgeoning, piercing, and slashing damage.

Classes: Sorcerer, Warlock, Wizard
This steals some class-defining features and gives it to a caster for a 4th level slot.


True Strike
1st-level Divination
Casting Time: 1 bonus action
Range: 30 feet
Components: V, S
Duration: Instantaneous

Choose a creature within range (including yourself). That creature has advantage on attack rolls until the end of its next turn.

Classes: Bard, Sorcerer, Warlock, Wizard
Keep this a cantrip; it can be balanced that way.

I mean, you'll have to tweak it again, but still.

[rferries]

Sorry for the delay and thanks for the comments!


I'd keep this as Arcane Sword. It is a replacement, renaming seems confusing.

You could also up its size so it has a 10' reach.

A 6th level spiritual weapon is a bonus action to cast, and deals 3d8+stat damage. So lower level and better action economy. The parry and OA is cute, but don't know if it is enough.

Although the name is a classic I edited it to streamline with spiritual weapon.

I've added the reach, thanks!

It was based on an upscaled spiritual weapon, with the reactions you noted, and importantly a 60-foot fly speed. I've bumped up the base damage to 4d8 but I'm thinking that might be a bit much already. I may just stat up a summonable "arcane sword" monster but that's straying rather far from both older and contemporary D&D.


So you added 3d8 so it matches fireball.

(a) fireball is a high damage spell, don't balance against it.

(b) undead aren't immune to necrotic damage in 5e.

(c) do something more interesting than damage and undead/anti-undead friendly fireball with a bigger AOE.

What if it made a zone that lasted for 1 minute on top of the AOE damage? Like:

Duration 1 minute.

This creates a circle of death with a 60' radius within range. All movement within or above this zone requires an extra foot of movement for every foot of movement you move. The first time a creature is in the zone they take 15 necrotic damage. In addition, all creatures within the zone when it is created, who enter the zone, or who start their turn in the zone are poisoned for the duration of the spell, gain a level of exhaustion, and suffer 4d6 necrotic damage unless they make a constitution saving throw. Once you have failed this saving throw you do not have to make it again, but creatures who succeed at it have to repeat it each time they trigger it.

This is now a "fireball" that makes an area cursed, at least for a minute.

It seems to me that higher level spells should be better than lower level spells even if upcast to the same level - compare resilient sphere/force cage, fireball/meteor swarm, etc. I take your point about it not being particularly exciting but these fixes were intended to keep as much of the original flavour as possible (apart from weird, that is). n.b. The necrotic/radiant transparency exceptions were a nod to older editions.

I quite like your idea! It's different enough that I would consider it an entirely new spell rather than a "fix", but it's honestly superior and worthy of your own post.


I like the "fire again", but I think the "once I hit you I can repeat it" is worthwhile.

After trying to fix witch bolt I'm already sick of the "sustained fire" mechanic for spells haha. I buffed the healing though.


No concentration? I get the old one was too weak, this one seems a bit too strong.

Also, shared quiver abuse.

I'd rather not add concentration but I've deleted the scaling damage. The quiver abuse was semi-intentional e.g. if you're currently helping an army.


I'd take the original thanks.

Yes, that seems to be the consensus. I've removed my fix, will possibly add it to a post for new spells.


This steals some class-defining features and gives it to a caster for a 4th level slot.

I've edited the upcast section.


Keep this a cantrip; it can be balanced that way.

I mean, you'll have to tweak it again, but still.

Unfortunately I think this will have to be the final version - if it's a cantrip it can't really have a useful mechanic, due to the gish abuse pointed out by the other poster.

Thanks again for your comments!

[Yakk]

Here is an example of a fun cantrip true strike:

True Strike + Cantrip
Casting Time 1 action
Components S
Duration Up to 1 round (Concentration)
Range: Any creature you can see
School: Divination

You extend your hand and point a finger at a target in range. Your magic grants you a brief Insight into the target's defenses. On your next turn, you gain advantage on your first Attack roll against the target and the attack deals +1d12 damage, provided that this spell hasn't ended.

At 5th level the attack deals an extra die of damage, and again at 11th and 17th level, for a total of +4d12 damage.

---

The fundamental problem with true strike is that advantage isn't as good as 2 actions in 99% of situations.

To fix this, True Strike now delays your damage (bad), but gives you the dice back you'd get from making a cantrip attack, and gives advantage on that (combined) attack.

It is now very good for a sniper (as it should be), and decent in other situations. The concentration and damage delay cost is significant.

The most powerful user of this might be a Bladesinger who has no other use for concentration this fight.

Fighting a foe with 16 AC and +1 will save.

The bladesinger has 18 int, 16 dex and a +1 rapier (15 save DC, +7 to hit)

Bob uses True Strike.
Alice uses Toll the Dead.

Fight lasts 3 rounds.

Bob gets 4 attacks and 2 True Strike boosted attacks.

Alice gets 3 attacks and 3 Tolls.

To-hit is 9+;
A "bare" attack is worth 4.725 damage.
A toll the dead (I'll assume creature is wounded) is 8.45 damage.
A "true" strike is worth 0.84 * (4.5+3+13) + .01 * (4.5+13) = 17.395 damage.

Bob does 53.69 damage
Alice does 39.525 damage

---

A 20 strength / 14 int EK7ish with GWF, GWM and a +1 Greataxe using -5/+10.

Bob does:
True Strike, normal swing round 1 (+9 to hit, 1d12+6 (13.3, 7.3 crit) damage)
True Strike, -5/+10 round 2 (+4 to hit, advantage, 3d12+16 (36.3, 20.3 crit) damage)
True Strike, -5/+10 round 3 (+4 to hit, advantage, 3d12+16 (36.3, 20.3 crit) damage)

Alice does GFB/Normal swing each round.
GFB is +9 to hit for 1d12+1d8+6 (17.8, 11.8 crit, plus 6.5(+4.5 crit) splash)

AC 16 has 70%/5% for normal swing, and 70%/10% for a -5/+10 advantage swing.

Normal swings do 9.7 damage per swing.
True Strike swings do 27.4 damage per swing.
GFB swings do 13.1 damage per swing (plus 4.8 splash)

Bob does a total of 64.5 (+27.4 per additional round)
Alice does a total of 68.4 and 14.4 splash (+22.8 4.8 splash per additional round)

This is pretty close. If Bob can manage an ambush they get ahead.

[Yakk]

Enervation, revised:

When you first cast the spell, or as an action until the spell ends, you can force a target to make a Dexterity saving throw. On a successful save, the target takes 2d8 necrotic damage. On a failed save, the target takes 4d8 necrotic damage, and a crackling connection of necrotic energy joins you and the creature.

In addition, you can also spend an action until the spell ends to deal 4d8 necrotic damage to every creature who has failed a saving throw against the spell.

Issues:
Spells in general aren't supposed to force multiple save-or-sucks. Being able to suck life out of someone with an action is, however, not as bad a save-or-suck.

This also opens up some fun tactical choices.

You can repeatedly attempt to get one target. You can connect to 3 targets, then suck the life out of all of them. You can suck one creature dry, then move onto the next one.

You can spend 5 rounds getting 5 targets, then 5 rounds sucking them all dry; if everyone fails a save, that is 120d8 total damage. Which is ridiculous, but does require 10 actions and 10 turns and 100% accuracy and concentration and a long setup and damage spread over 5 creatures.

Using the "second targets are worth half rule" and "damage on round n is worth 1/n", we get:

4d8 + 4d8/4 + 4d8/6 + 4d8/8 + 4d8/10 + 20d8*3/5/6 + 20d8*3/5/7 + 20d8*3/5/8 + 20d8*3/5/9 + 20d8*3/5/10

18 + 18/4 + 18/6 + 18/8 + 18/10 + 90*3/5/6 + 90*3/5/7 + 90*3/5/8 + 90*3/5/9 + 90*3/5/10

= 64.4 weighted damage for 2.93 weighted actions (at 1/n cost), for 22.0 weighted damage per weighted action.

An at-will cantrip like toll the dead on an injured foe is 19.5 damage (also, weighted damage per weighted action). So this upgraded spell isn't all that insane.

Getting large numbers of damage requires multiple targets and a long setup, which I don't object to rewarding. The HP harvest when you are sucking the life out of many foes is also ridiculously fun and thematic. Your necromancer can stand there with crackling bolts of necrotic energy making their wounds close up and heal.

Still, it is stronger than the junk original. And it is also stronger than the version you wrote.