In my Princes of the Apocalypse, I've taken to creating some magic items to seed my campaign with:Most scholars agree that bloodfire was forged by the Old Pyre Omtar, the legendary azer smith whose works are highly sought after, 300 years after his disappearance.
Magic weapon (warhammer), rare (requires attunement)
You gain a +1 to attack and damage rolls with this magic weapon.
In addition, as a reaction you mays pend one or more hit dice when you deal damage to a creature. Roll each hit die spent and deal that much fire damage to target creature.
Finally, you gain a +1 to death checks while attuned to a bloodfire.