[3.5] Gestalt Sorceror//Cleric Final Boss

[RMS Oceanic]

Hi,

I'm putting the final details on my first adventure (level 10 or 11 party), but a biggie is an appropriate final boss. I'm thinking a Sorceror 14//Cleric-or-Favored-Soul 14, with Rapid Metamagic/Quicken Spell, and he'd focus on debuffs and area of effect damage rather than being a CoDzilla. I dunno if it's too powerful, but he has an insta kill weak button that I hope I can get the PCs to clue in on. Could someone recommend appropriate spells for a build like this?

[Beardbarian]

Some info about PCs?

[RMS Oceanic]

Some info about PCs?

They haven't actually submitted characters to me, but there will be 5-6 of them, and I have inferred from their hints that the four classic roles will be adequately covered.

[Beardbarian]

They haven't actually submitted characters to me, but there will be 5-6 of them, and I have inferred from their hints that the four classic roles will be adequately covered.

Classic or Gestalt characters? This is important A LOT

[RMS Oceanic]

Classic or Gestalt characters? This is important A LOT

Oh everything beyond simple monsters will be Gestalt. I've rolled up a Soulbow Sniper and a Wererat Swordsage for them to take on before they get to this guy.

[chronomatophobe]

Five or six gestalt characters will spit this guy out in a round or two if they're a little optimized, unless you give him minions or pull some serious cheese.

Or if they've been drained of two-thirds of their resources before they get to him.

[RMS Oceanic]

So I've decided to try and throw something together:

Sorcerer 15//Favored Soul of Nerull 15 (Neutral Evil)
STR 10
DEX 14
CON 14
INT 12
WIS 18
CHA 22

Feats: Quicken Spell, Rapid Metamagic, True Believer?

Equipment: Wisdom/Charisma boosters, Standard resistance boosters, Nerull's Incense Relic?

Arcane Spells: Magic Missile, Grease, Fireball, Fog Cloud, Solid Fog, Stinking Cloud, Cloudkill - Seeing a pattern? - Overland Flight, Arcane Fusion, Delayed Blast Fireball, Dominate Person
Divine Spells: Hold Person, Greater Harm, Heal, Mass Inflict Moderate Wounds, Flame Strike, Forbiddance (roleplaying reason), Summon Monster VII

I'm thinking of giving him a right hand man to wonder through these clouds I'm summoning and attack: Maybe a Warlock//Rogue?