Lich

The Lich is a Heartless that is found as a boss in ''Kingdom Hearts III.

Kingdom Hearts III
''This haunting horror held the hearts of Sora's friends hostage. Time and again, Sora fought it back, but with each hard-won victory, it would simply slough its form and depart to another world.''

Its broad arsenal of magic made it a formidable foe to face alone, but in thend no Heartless could match the strength of Sora's resolve.

Kingdom Hearts III
The Lich first appears in Olympus after Sora returns from The Final World. The Heartless takes captive the hearts of Sora's friends, leading the Keyblade wielder in a chase across the worlds he had visted before. The Lich eventually meets its end in San Fransokyo, the hearts it had captured having been released and returned.

Origin
A lich (derived from the Old English word līċ, meaning "corpse") is a creature featured in fantasy fiction, usually resulting from the transformation of a individual skilled in magic such as necromancy in order to achieve immortality.