Doom knight

Doom knight: The cursed, undead corruptions of once-upright paladins who fell from grace, doom knights are the scourge of all lands over which they hold dominion.

Special abilities
Like many undead, the doom knight is immune to ability drain, critical hits, death magic, disease, level drain, mind-affecting spells, paralysis, poison, and sneak attacks. In addition, this creature has damage reduction 15/+1 and spell resistance 12.

A doom knight has several spell-like abilities that mimic spells but are not subject to interruption or counterspelling. These abilities (and their uses per day) are dispel magic (x2), fireball (x1), power word, stun (x1), and see invisibility (x3). These abilities have a caster level of 9. Furthermore, a doom knight can use an aura of fear twice per day.