Here we go:
Killjoy, False Keraptis Efreeti
Large Outsider (Extraplanar, Fire)
Hit Dice: 10d8+35 (80 hp)
Initiative: +7
Speed: 20 ft. (4 squares), fly 40 ft. (perfect)
Armor Class: 18 (–1 size, +3 Dex, +6 natural), touch 12, flat-footed 15
Base Attack/Grapple: +10/+20
Attack: Slam +18 melee (1d8+6 plus 1d6 fire) or Blackrazor +21 melee (2d6+12/19-20)
Full Attack: 2 slams +18 melee (1d8+6 plus 1d6 fire) or Blackrazor +21/+16 melee (2d6+12/19-20)
Space/Reach: 10 ft./ 10 ft.
Special Attacks: Change size, heat, hierarchical mind, partial imprint, spell-like abilities
Special Qualities: Changes shape, darkvision 60 ft., immunity to fire, plane shift, spell resistance 20, telepathy 100 ft., vulnerability to cold
Saves: Fort +12, Ref +13, Will +12
Abilities: Str 23, Dex 17, Con 14, Int 12, Wis 15, Cha 19
Skills: Bluff +20, Craft (any one) +17, Concentration +18, Diplomacy +11, Disguise +7 (+9 acting), Intimidate +22, Listen +18, Move Silently +19, Sense Motive +18, Spellcraft +17, Spot +18
Feats: Combat Casting, Combat Reflexes, Dodge, Improved Initiative (B), Quicken Spell-Like Ability (scorching ray)
Environment: Elemental Plane of Fire
Organization: Solitary or hierarchical mind (Killjoy plus up to 30 subsumed minds)
Challenge Rating: 12
Treasure: Standard coins; double goods; standard items
Alignment: Lawful evil
Advancement: 11–15 HD (Large); 16–30 HD (Huge)
Level Adjustment: -
Killjoy has 30 Subsumed Minds. The benefits of these are reflected in his statistics, and he additionally receives a +3 bonus to any unlisted skill check or ability check. The save DCs of his Su abilities are increased by +1.
Spell-Like Abilities: At will—detect magic, produce flame, pyrotechnics (DC 14), scorching ray (1 ray only); 3/day—invisibility, magic missile, wall of fire (DC 18); 2/day-black tentacles*, lightning bolt*, mirror image*;1/day—acid arrow, arcane mark, circle of death, cloudkill, cone of cold, dimension door, fireball, grant up to three wishes (to nongenies only), gaseous form, knock, permanent image (DC 20), read magic, sleep, slow, stoneskin, touch of fatigue, wall of force, wind wall, true seeing. Caster level 15th. The save DCs are Charisma-based. *These spell-like abilities have one extra use per day due to Killjoy's Subsumed Minds. As he loses Subsumed Minds, he loses one use per day of each of these SLAs.