Confusion on Dispel Magic & others

[Noctani]

I am a little confused on how dispel magic works after going through the rule book and reading a few forums with different conclusions.

This is how I currently understand it.

When a player is targeting a creature who has multiple ongoing effects from magic items and spells; the spells are affected by the magic items are not.

A player can target magic objects on npcs and suppress the item for 1d4 turns after a successful check.

If a player targets an area all active spells are dispelled ( one check for each effect ) if the check is successful.

An area dispel or target creature dispel does not affect continuous magic items.

2nd Question

Background

I am currently running a game where the players are fighting the main villain for the first time after several months of campaigning, and one of my players has just discovered the great use of greater dispel magic. I last left off describing the main villain to the heroes. Immediately, I was swamped with questions but held them off for the next meeting.

The players know very little about the villains capabilities and I want it to stay that way, otherwise the casters will make the upcoming battles far less epic. There are two casters in the party, a tank melee type, and rogue who like to lace their weapons with poison.

This battle is not meant to kill the players or have the players kill the villain.

Both of the casters are about 120 feet from the main villain and are going to be asking for descriptions of the battlefield. (each has arcane sight) Party LVL is 17

The main villain is on a battletitan(huge dinosaur). I want to use it as partial cover to prevent the casters from neutralizing his magic items too quickly. I know they are going to want to know the aura of each of his items to figure out what to dispel but the mage has time stop so it could get ugly fast and in the end the players will decide.

So my question is two fold. Can the NPC's see identify and target his different items with arcane sight or is saying you can only identify one aura on the character and it's exuding from his entire body unfair? In addition, would malign fury(class feature made from magic oils) create an aura? If so how strong is it compared to a +5 weapon? Whats a 5+ Weapon compared to a caster lvl 15 item spell lvl 1?

Race: Half-Giant

LVL 1 Fighter Improved Initiative, Improved Unarmed Strike
LVL 2 Fighter Weapon Focus
LVL 3 Fighter Improved Grapple
LVL 4 Fighter Iron Will
LVL 5 Fighter
LVL 6 Occult Slayer Magical Defense +1, Weapon bond, Mage Slayer
LVL 7 Occult Slayer Vicious strike, mind over magic 1/day
LVL 8 Occult Slayer Auravision, magical defense +2
LVL 9 Occult Slayer Mind over magic 2/day, nondetection cloak, Combat Reflexes
LVL 10 Occult Slayer Blank thoughts, magic defense +3
LVL 11 Corrupt Avenger Armor casting, detect sworn foe, sworn foe +2, taunt suppression
LVL 12 Corrupt Avenger Tainted strike 1/day, Survivor’s luck
LVL 13 Corrupt Avenger Grim Resolve
LVL 14 Dark Warrior BMO MFury 3x per day
LVL 15 Dark Warrior Darkling Weapon, improved flight
LVL 16 Dark Warrior BME Power Attack
LVL 17 Dark Warrior BMO +10ft speed
LVL 18 Dark Warrior True Believer, Scarred Flesh, extended reach
LVL 19 Dark Warrior BME Quick Draw
LVL 20 Pious Templar Mettle

The main villain is grafted
Membranous Wings
Long Arm
Grappling Tentacle

Items (Many are custom)

Head: Circlet of Absorption (Ioun stone, 40 spell lvls), w/Pectoral Manueverability (improve manueverability by 1)
Cloak of the Resistance +5 resistance to saving throws +5 to Charisma
Amulet Scarab of Protection & wisdom +4 wisdom (immune to death, energy drain, ability, lvl drain
Armor Don't know
Ring of Lovers Love +4 morale bonus to saves, haste
Ring of the Evasion +4 Lucky bonus to saves
Gloves of dexterity +4 Dexterity, combat alertness(spell continuous) +5 initiative
Bracers of the Giant +4 Con +4 STR, sign continuous spell
Belt of Endurance +4 Insight bonus to saves, see invisibility
Boots of Teleportation 3 per day
Weapon +1 Ghost Touch +1 Magebane +2 spell lance of magic dispel greater(keyed at forging)
Ring of the Elements = cast energy immunity 4x per day (cast prior)

I suppose I am also looking for some all around mentorship because I am starting to feel like the players are really setting their expectations high.

[Deophaun]

With detect magic, you are close. Your one error is here:

If a player targets an area all active spells are dispelled ( one check for each effect ) if the check is successful.
While all active area spells get a check, if there are creatures/objects with multiple spells on them, then only one of those spells per creature/object is dispelled. You start with the highest-level spell on the creature/object, and you make checks in descending order until you either dispel an effect, or fail all checks.

This battle is not meant to kill the players or have the players kill the villain.
I hope you haven't pinned your hopes on the villain surviving. Putting an NPC you aren't prepared to have killed in front of murder hobos is a lot like pointing a gun at something you do not intend to destroy.

So my question is two fold. Can the NPC's see identify and target his different items with arcane sight or is saying you can only identify one aura on the character and it's exuding from his entire body unfair?
They can see, identify, and target each item. This is pretty much the whole reason to have arcane sight on in the first place. By the time you can cast level 3 spells, saying "the whole thing is magical" is already pretty useless information.

In addition, would malign fury(class feature made from magic oils) create an aura?
If it's made from magic oils, most likely. I'd use the class level of the character using the feature to determine aura strength

Whats a 5+ Weapon compared to a caster lvl 15 item spell lvl 1?
The only thing that determines an aura's strength is its caster level. So both the sword and the level 1 spell have the same strength.

[Noctani]

Okay, that clarifies alot but I don't understand how the players can target all of them based upon the aura. Thank you Deophaun. But there are still some things I'd like better explained.

But, when I imagine this in my head. I don't see the players being able to target objects they have no line of sight of. How can they target rings behind gloves, or a circlet behind a robe, or anything not within their line of sight behind the battle titan. (I would think that counts just as much as 1 inch of common metal, which the spell cannot penetrate) I can understand they know the magic items are there but since they have to target the object and not the aura I don't think they can suppress the items they can't see. Is it just magic? I don't want to rob my players by being presumptuous either. Are you sure the objects can still be targetted?

[Urpriest]

The battletitan is a creature, so nothing is "behind" it. Creatures don't fill their space, so at most they can provide cover to other creatures behind them. They can't completely block line of sight.

[Noctani]

Thank you, Ur-priest. All my questions have been answered.