Lich

In Dungeons & Dragons(D&D) and derivative games, a lich is a wizard or cleric who seeks to defy death by magical means. They transform theirselves into an undead state by means of various unholy rituals and store their soul in a magical jar called a "phylactery." The name comes from the Old English lic, (pronounced the sam) which means "corpse."

A lich retains the abilities he or she possessed in life, but they also have had a virtual eternity to practice new skills and inevitably become very formidable. The most powerful example of a Lich in D&D is known as Vecna[?].