Magmarath Molten Blaster (Patreon)

Weapon (crossbow, heavy or light), very rare (requires attunement)

Molten veins glimmer from beneath this magic weapon's volcanic body. The crossbow magically creates and loads its own ammunition whenever the drawstring is pulled back, forming a bolt of condensed lava each time. On a hit, it deals 2d8 fire damage, instead of the weapon's normal damage. You still add your Dexterity modifier to this damage roll. The ammunition crumbles and turns to ash immediately after it hits or misses a target or if it's removed from the crossbow.

The crossbow has 5 charges and regains all expended charges daily at dawn. While holding the crossbow, you can expend 1 of its charges using an action. When you do, the crossbow magically projects an explosive mote of fire, which vaguely resembles a fiery mephit. If the last target you hit with one of the crossbow's lava bolts is still within the weapon's normal range, the mote magically strikes that target and explodes. Roll 4d6. The target takes fire damage equal to the total, and each creature within 10 feet of the explosion (not including the target) must succeed on a DC 16 Dexterity saving throw or take fire damage equal to half the total.

"I heard they use mephits to make these down in Magmarath. Is that true?"

"Oh yeah, definitely. Don't feel too bad, though. Nasty blighters, those things. Pay attention when you draw that string back: sometimes you still can hear 'em screaming."