ATROPAL

Large Undead (Evil, Extraplanar, Lawful)
Hit Dice: 66d12 (792 hp)
Initiative: +6 (+2 Dex, +4 Improved Initiative)
Speed: 5 ft., fly 240 ft. (perfect)
AC: 51 (-1 size, +2 Dex, +40 natural)
Base Attack /Grapple: +33/+53
Attack: Touch +49 (2d6 Con drain/19-20) melee touch
Full Attack: 2 touches +49 (2d6 Con drain/19-20) melee touch, eye ray +30 (negative level damage/19-20) ranged touch
Space/Reach: 10 ft/10 ft.
Special Attacks: Constitution drain, energy drain (2d4 negative levels, Fort DC 59), spell-like abilities, summon nightcrawler
Special Qualities: Abomination traits, undead traits, rebuke/command undead, regeneration 20, SR 42, DR 15/good and epic and silver, negative energy aura
Saves: Fort +22, Ref +26, Will +43
Abilities: Str 43, Dex 15, Con -, Int 28, Wis 22, Cha 42
Skills: Bluff +85, Concentration +85, Diplomacy +97, Hide -2, Jump +1, Intimidate +91, Knowledge (arcana, history, religion, the planes) +78, Listen +77, Search +78, Sense Motive +75, Spellcraft +84, Spot +77
Feats: Alertness, Cleave, Dodge, Expertise, Great Cleave, Improved Bull Rush, Improved Critical (touch), Improved Critical (eye ray), Improved Initiative, Iron Will, Lightning Reflexes, Mobility, Power Attack, Quicken Spell-Like Ability, Run, Spring Attack, Weapon Focus (touch), Weapon Focus (eye ray), Whirlwind Attack
Epic Feats: Devastating Critical (touch), Overwhelming Critical (touch), Undead Mastery, Zone of Animation
Climate/Terrain: Any
Organization: Solitary
Challenge Rating: 30
Treasure: Standard
Alignment: Always lawful evil
Advancement: 67-80 HD (Large); 81-100 HD (Huge)
An atropal's natural weapons are treated as epic, evil, and lawful-aligned for the purpose of overcoming damage reduction.

Combat

Spell-Like Abilities: At will-animate dead, blasphemy, create greater undead, create undead, cone of cold, desecrate, greater dispelling, finger of death, improved invisibility, plane shift, slay living, speak with dead, spectral hand, teleport with-out error, unholy aura; 5/day-haste, project image, weird. Caster level 30th; save DC 26 + spell level.
The save DCs are Charisma-based
Rebuke/Command Undead (Su): Atropals can rebuke or command undead as a cleric with a level equal to the atropal's HD + 6.
Negative Energy Aura (Su): A 30-foot-radius spread negative energy aura spreads from each atropal. All undead in the field (including the atropal) are treated as if having turn resistance +20 and a negative energy version of fast healing 20. Living creatures in the aura are treated as having ten negative levels unless they have some sort of negative energy protection or protection from evil. Creatures with 10 or fewer HD or levels perish (and, at the atropal's option, rise as spectres under the atropal's command 1 minute later).
Constitution Drain (Su): When the atropal hits a living opponent with a touch attack, the opponent takes 5 points of permanent Constitution drain, or 10 points on a critical hit. The atropal heals 20 points of damage, or 40 points on a critical hit, whenever it drains Constitution, gaining any excess as temporary hit points. These temporary hit points last a maximum of 1 hour. The attack allows a Fortitude save (DC 59). The DC is Charisma-based.
Energy Drain (Su): When the atropal hits with a ranged touch attack (a ray of darkness that it shoots from one eye to a range of 400 feet), the resultant energy drain bestows four negative levels, or eight negative levels on a critical hit. For each negative level bestowed on an opponent, the atropal heals 10 points of damage, or 20 on a critical hit, gaining any excess as temporary hit points. These temporary hit points last a maximum of 1 hour. After 24 hours have passed, the afflicted opponent must attempt a Fortitude save (DC 59) for each negative level. If successful, the negative level goes away with no harm to the creature; otherwise, the creature's level decreases by one. The DC is Charisma-based.
Regeneration (Ex): Atropals take normal damage from good weapons or sentient weapons (or otherwise living weapons).
Summon Nightcrawler (Sp): Five times per day an atropal can summon a nightcrawler.
Abomination Traits: Immune to polymorphing, petrification, and other form-altering attacks; not subject to energy drain, ability drain, ability damage, or death from massive damage; immune to mind-affecting effects; fire resistance 20; cold resistance 20; nondetection; true seeing at will; blindsight 500 ft.; telepathy out to 1,000 ft.
Undead Traits: Immune to poison, sleep, paralysis, stunning, disease, death, effects, necromantic effects, mind-affecting effects, and any effect requiring a Fortitude save unless it also works on objects. Not subject to critical hits, subdual damage, ability damage, ability drain, or energy drain. Negative energy heals. Not at risk of death from massive damage, but destroyed at 0 hit points or less. Darkvision 60 ft. Cannot be raised; resurrection works only if creature is willing.