In my Out of the Abyss game, I've taken to creating some magic items to seed my campaign with:Legend holds that the Hammer of Innocence was given to the Inquisitor, Grace von Damme, by Tyr himself to free the village of Laslo from a clutch of yugoloths. While the enchanted warhammer was said to have been buried with the Inquisitor, rumors have linked the Red Door to its theft for close to a decade.
Magic weapon (warhammer), very rare (requires attunement)
You gain a +2 to attack and damage rolls with this magic weapon.
In addition, you deal an additional 2d8 force damage against fiends.
Finally, if a fiend is possessing a creature that is struck with the warhammer it must make a DC 12 Wisdom saving throw, on a failure the creature is freed from possession.