Lich

Generally, Liches are Powerful Spellcasters who sought after Immortality and performed foul Rituals to become Undead.

They are very Intelligent and Powerful.

Types of Liches include:
 * Demilich. Very Powerful Liches who have no more need for a Body, So They shed their Bodies and become a Weak-looking, But immeasurably Powerful Skull
 * Alhoon. Mind-flayer Liches.
 * Baelnorn. Good Liches.
 * Archlich. More powerful Liches.
 * Dracolich. Dragon Liches.

The lesser Deity Vecna is an Archlich.

Other Liches
It is revealed that becoming a Magical Girl places the soul in a Soul Gem (effectively their phylactery) with the body, as Kyubey states, "being nothing more then external hardware".