Amulet of the Ultimate Sacrifice

This unassuming, weathered golden amulet hangs heavy from a brass chain. It can only be used by an evil- or good-aligned creature. To neutral or unaligned creatures, it appears worthless. While holding the amulet, a creature can take an action with an effect based on its alignment:

• If the user has any good alignment, it can lay the amulet around the neck of another creature's corpse. If the amulet remains on the corpse for 1 minute, the amulet turns to dust and the user dies instantly. The corpse then returns to life according to the rules of the true resurrection spell.
  
  
• If the user has any evil alignment, it can snap the amulet from its chain and press it to the chest of another creature within 5 feet. The target must succeed on a DC 20 Charisma saving throw. On a success, the amulet has no effect. On a failure, both the target and the user die instantly. In either case, the amulet then turns to dust.

Any deaths caused by this amulet is irreversible, short of casting a wish spell or divine intervention. The amulet itself can't be restored by any means whatsoever.