Fire Wand of the Sueloise

This magic wand may have been the device that caused the destruction of the Suel Empire. While you hold this magic wand, you can use a Magic Action to spend 3 charges and create a 60-foot Cube to a point that you can see within 120 feet of you. The Cube contains a rain of magical fire that burns everyone and everything. Each creature within the Cube must make a DC 19 Dexterity saving throw, taking 12d8 Fire damage on a failed save, or half as much damage on a successful one. On each of your next turns, you can spend a Bonus Action to maintain the Cube, and each creature that starts its turn there or enters the Cube for the first time on a turn must make a DC 19 Dexterity saving throw, taking 12d8 Fire damage on a failed save, or half as much damage on a successful one. Objects not carried or worn within the cube other than those made of mithral and adamantine take 12d8 Fire damage at the end of each of your turns as long as the Cube lasts. When you spend the last charge, roll a d20. On a 10 or lower, the wand explodes in a Sphere of 60-foot radius centered on you. Each creature within the sphere must make a DC 21 Dexterity saving throw, taking 24d8 fire damage on a failed save, or half as much damage on a successful one.

Recharge. The wand has 6 charges and recharges 1d6 spent charges daily at dawn.

Proficiency: simple, wand Source: Treasures from Oerth p. 34 (Homebrew)