Incendiary Cloud
ConjurationA swirling cloud of smoke shot through with white-hot embers appears in a 20-foot-radius sphere centered on a point within range. The cloud spreads around corners and is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. When the cloud appears, each creature in it must make a dexterity saving throw. A creature takes 10d8 fire damage on a failed save, or half as much damage on a successful one. A creature must also make this saving throw when it enters the spell's area for the first time on a turn or ends its turn there. The cloud moves 10 feet directly away from you in a direction that you choose at the start of each of your turns.
Spell Details
Player Guide
Position the cloud to divide enemy forces or trap enemies within its damaging radius while blocking line of sight for your allies' ranged attacks. Enemies inside take 10d8 fire damage on their turn (half on save), making it ideal for clustering foes. Combine with control spells to prevent enemies from leaving, or use it defensively to create a no-go zone that damages pursuers each turn.
Spell Combos
DM Tips
Clarify whether the cloud blocks vision for attacks originating inside it; RAW heavily obscured blocks all vision. Consider how wind or air currents might interact with the persistent effect in your setting.