Staff of Undying Friendship

Weapon (quarterstaff), rare (requires attunement)

This black cane can be used as a +1 quarterstaff. Additionally, while attuned to this item, undead are more amenable to your instruction and suggestion. Each time you finish a long rest undead treat you as if you are under the effects of the sanctuary spell until you trigger sanctuary to end.

Curse

While attuned to this staff any attempts to discern your creature type by arcane or religious methods treats you as though you are undead. Additionally, any magical means of determining your alignment will treat you as chaotic evil, regardless of what your alignment really is. Once attuned, you are linked with this staff until such time as another creature attunes to it, thus breaking your bond.