Banishment Bomb

 A black iron ball engraved with runes of banishment, this item is intended to even the playing field for baatezu outnumbered 10 to 1 by tanari on the battlefield by sending them directly back to the Abyss.

When activated, the bomb ticks down for 3 rounds. It can be activated early by being struck against a solid surface or thrown up to 40 feet. When it goes off, it subjects every creature within 20 feet to an effect equivalent to the Banishment spell. They must succeed a DC 16 Charisma saving throw or be shunted back to their plane of origin. Fiends have disadvantage on this save, and are frightened even if they succeed.