Level 20 Multiclass idea- Inferno Cannon

[Undyne]

Race: Human (Variant), taking a +1 to Cha and Int. We need both above 13 at minimum. Take Elemental Adept (Fire).
Class: Sorcerer (Draconic: Red, Brass, or Gold)6, Wizard (Evocation)14
Metamagics: Quicken, Twin
Spells: Any dice-heavy Fire spells (Burning Hands, Scorching Ray, Fireball, Fire Bolt)
Goal: Quicken a 5th level Fire Spell that forces a Save, maxing the damage with the Wizards Overchannel (5th Level Fireball would be my go-to), then Twin Fire Bolt to clean up any survivors.

Had this idea for a LV20 one-shot character after watching ZeeBashew's video on Fire Bolt. Thoughts?

[malachi]

If you're simply looking for the highest single-target damage, you might consider looking at the nuclear wizard (http://www.giantitp.com/forums/showsinglepost.php?p=23998967&postcount=170).

Your build lets you do good damage to one target 1/day without hurting yourself (if you do it a second time, you take 10d12 damage), but leaves you without 8th or 9th level spells (though you do have the spell slots).

Sorcerer gives you +CHA to damage with one element type (with whatever limitations the errata / sage advice imposed on it) and a pool of 6 sorcery points to work with (You can Quicken + Twin on two turns before you're empty and need to burn spells for more SP), but you're losing out on 8th and 9th level spells for potentially an extra +CHA+4d10+INT+CHA+4d10+INT+CHA damage to one target over the course of the day (unless you burn more spell slots for SP).

Your build: 66+INT+CHA+4d10+INT+CHA= 38 damage (target saves, and firebolt misses) to 98 damage (target fails save and firebolt hits) to one target. You can do this twice per day, and don't have access to level 8 or 9 spells (though you do have the slots). Your AC is 13+DEX, and you need high CHA, so you can't pump your DEX much.

Nuclear wizard w/ 5th level non-overchanneled Magic Missile: 7*(2.5+1+INT+PROF) = 101.5 force damage (or 0, if the target casts shield or is a helm horror). Plus, potentially, another spell from Action Surge. This can be done multiple times to one target, to 1 target / short rest. This build has fewer spell slots than your build (one less 6th and 7th level slot), but has a SR-recharging 1st level slot and Action Surge, and has 8th and 9th level spells (like Wish). Additionally, your AC is 19 (assuming you have 14 DEX).



So your build isn't the best possible.
Also, it may be better to overchannel an ongoing damage spell like Dawn instead of Fireball, since it deals damage multiple times (although I'm not sure of any good fire DoTs that you can move around to guarantee the targets take extra damage).

[Dork_Forge]

If you're simply looking for the highest single-target damage, you might consider looking at the nuclear wizard (http://www.giantitp.com/forums/showsinglepost.php?p=23998967&postcount=170).

Your build lets you do good damage to one target 1/day without hurting yourself (if you do it a second time, you take 10d12 damage), but leaves you without 8th or 9th level spells (though you do have the spell slots).

Sorcerer gives you +CHA to damage with one element type (with whatever limitations the errata / sage advice imposed on it) and a pool of 6 sorcery points to work with (You can Quicken + Twin on two turns before you're empty and need to burn spells for more SP), but you're losing out on 8th and 9th level spells for potentially an extra +CHA+4d10+INT+CHA+4d10+INT+CHA damage to one target over the course of the day (unless you burn more spell slots for SP).

Your build: 66+INT+CHA+4d10+INT+CHA= 38 damage (target saves, and firebolt misses) to 98 damage (target fails save and firebolt hits) to one target. You can do this twice per day, and don't have access to level 8 or 9 spells (though you do have the slots). Your AC is 13+DEX, and you need high CHA, so you can't pump your DEX much.

Nuclear wizard w/ 5th level non-overchanneled Magic Missile: 7*(2.5+1+INT+PROF) = 101.5 force damage (or 0, if the target casts shield or is a helm horror). Plus, potentially, another spell from Action Surge. This can be done multiple times to one target, to 1 target / short rest. This build has fewer spell slots than your build (one less 6th and 7th level slot), but has a SR-recharging 1st level slot and Action Surge, and has 8th and 9th level spells (like Wish). Additionally, your AC is 19 (assuming you have 14 DEX).



So your build isn't the best possible.
Also, it may be better to overchannel an ongoing damage spell like Dawn instead of Fireball, since it deals damage multiple times (although I'm not sure of any good fire DoTs that you can move around to guarantee the targets take extra damage).

From the mention of twinning firebolt to clean up I imagine this is more crowd orientated. In that case the build isn't the most optimised but is certainly good at cleaning the board.