Bone blade

Bone blade was a spell that conjured a bladed weapon, made out of bone, that could be wielded by the caster or any of their allies.

Effects
The blade produced was considered a magical weapon that was particularly destructive towards the undead and could even destroy them outright. The blade was unbreakable until the spell's duration ended, whereupon it would dissolve into dust.

Development
This spell was created by the lich Shangalar the Black, before achieving lichdom. Its written origin was in his personal spellbook.

Components
This spell had somatic, verbal, and material components, requiring a normal bladed weapon and a piece of bone, both of which would be destroyed in its casting.