Demilich

Demiliches are wiser, older and far deadlier than common liches.

A demilich has most of the usual undead immunities, specifically to critical hits, disease, level drain, ability drain, mind-affecting spells, paralysis, poison, and sneak attacks. However, this creature does not have the usual undead immunity to death magic. In addition, a demilich is immune to all spells (excluding epic spells).

The attacks of a demilich inflict paralyzing touch on-hit. In addition, this creature has the following abilities (with a caster level of 15).

Furthermore, this creature is a a level 21 wizard with the following spells prepared.