Faerun's Spellplague: My Way
It's a Moonblade
+3 Keen Shocking Burst Elfblade (damage like a longsword, crits like a rapier, finessable) of Returning. Grants wielder Dismissal 1/day, and allows the wielder to create a shadow duplicate of herself at will. Also puts the wielder under a permanent Deathwatch effect. (Wielder knows the exact hit points remaining on any character in sight)
Can only be wielded by someone of good alignment and elven blood.
Weapon bonds to the wielder permanently until death. Wielder cannot be more than a stride away from the weapon or grow faint. If the wielder willfully separates herself from the blade, they must make a fortitude save equal to the distance in feet or die.
Upon first use of the blade, the would-be wielder must roll d%, and roll in the top 10% or be subject to a Finger of Death spell targeting her. If the wielder survives Finger of Death, they are hit (no save) by a Harm spell. The blade then goes dormant. It becomes nothing more than a +3 Elfblade to the would-be wielder. If another heir would become the wielder, they must also roll d%.
The Moonblade of Delwa’s House can only be wielded by an heir of that house. It passed to his half-drow wife after his older brother, the prior wielder of the blade, was slain in the assault on Mephistopheles’ Lair.
The blade’s purpose is to select the new Elven Court of New Myth Drannor.