I love the idea. From Wikipedia: Good liches are presented in Monster Compendium: Monsters of Faerûn, a supplementary rule book for the D&D 3rd edition rules. Good liches differ in that they have sought undeath for a noble cause, to protect a place, a loved one, or to pursue an important quest.

I love that you pulled from the Wiki- I originally tried to as well but had limited characters in my post 😆 glad you appreciate the idea of a “good” lich! Baelnorns have such cool lore