Horn of Undead Enmity
The haunting sound of this bone horn forces undead to turn against their own allies.
Wondrous Item 65,000 gp
Power (Charm) Daily (Standard Action)
When you sound the horn, make an attack: Close blast 5; targets undead only; +20 vs. Will. On a hit, the target makes its next attack against one of its adjacent allies. If it has no adjacent allies, it charges its nearest ally. If the target can't attack or charge, it moves its speed away from you.
Published in Adventurer's Vault, page(s) 173.