Weapon of Death

You imbue a weapon you touch with unholy power. Until the spell ends, weapon attacks made with it deal an extra 2d8 necrotic damage on a hit. If the weapon isn’t already a magic weapon, it becomes one for the duration.

As a bonus action on your turn, you can dismiss this spell and cause the weapon to emit a sickening, necrotic aura. Creatures of your choice that you can see within 30 feet of the weapon must make a Constitution saving throw. On a failed save, a creature takes 4d8 necrotic damage, and it falls prone. On a successful save, a creature takes half as much damage and isn’t prone.