Weapon (Bow), Rare (Requires Attunement)
There is a vast region of black glassy crags in the Lost Hills known as the Obsidian Cliffs. Streams and ponds in the area hold scalding water that fills the air with steaming fog on cold mornings. The people that live in the area are distinguished for their skill at taming fire elementals.
The Obsidian Fire Bow exemplifies the work of this discreet tribe. The elemental trapped inside the weapon can produce marvelous effects for the wielder; though, it would be wise to handle the bow with care. Elementals tend to be cantankerous about being locked away to do the bidding of fleshy folk.
Mechanic
As a bonus action, you can draw the bow and speak a command word; luz, Illumin, or Fugor. Doing so infuses your arrow with magical energy. On your next ranged attack action with this bow, you gain one of the following abilities.
Luz – Choose a point within range. When your arrow reaches that point, it bursts in an explosion of light. Bright light fills a 30-foot sphere centered on the location you chose. The light lasts for two rounds.
Illumin – Choose a point within range. When your arrow strikes that point, a 10-foot-square area around that point erupts in flames. Any creature in the area when the blaze erupts must succeed on a Dexterity saving throw (DC 13) or take 1d8 fire damage. A creature must also make the saving throw when it enters the area for the first time on a turn or ends its turn there.
Fugor – Make a normal ranged attack. If the attack hits, the target takes 1d8 Fire damage and catches on fire. The target takes 1d8 Fire damage at the start of its turn until someone takes an action to douse the flames.
If this bow is cracked or destroyed, it unleashes a fire elemental. The fire elemental will rage for 10 minutes before it calms and snuffs itself out.