Awakened Undead (trait)
Whether by explicit creation by a powerful necromancer or Lich, or the natural result of an undead thrall developing a true sentience by happenstance, this character is an Awakened Undead. Possessed of a personality, willpower, and the fundamental desire to continue existing, they can no longer be controlled by baser magics. More powerful necromantic domination will still work of course, as will more mundane contrivances such as "reason" and "bargaining".