Inferno Sling weapon, rare (requires attunement)

This sling is made from dark leather, painted with a bright orange motif. It smells of smoke and sulphur when you fire it. This item has 10 charges and regains 1d8+2 charges each day at dawn.

When you make an attack with this sling you can expend a charge and as you do so the ammunition begins smoking before it ignites in a fiery trail to your target. When you make an attack in this way you deal an additional 2d6 fire damage on a hit.   If you instead expend 4 charges while making an attack the ammunition explodes into a fireball on contact with a creature or surface. Each creature in a 20-foot-radius sphere centered on that point must make a DC 15 Dexterity saving throw.  A target takes 6d6 fire damage on a failed save, or half as much damage on a successful one. The fire spreads around corners and it ignites flammable objects in the area that aren’t being worn or carried.