Brook's Arson

You create a magical Molotov in your hand. You may throw the Molotov creating a 5 ft cube filled with magical flames. Any creature in the burning space must make a Dexterity saving throw or take fire damage equal to your spellcasting modifier(a minimum of 1). A creature must also make the saving throw when it moves into the burning space for the first time on a turn. If a creature ends its turn in the flames it must make the saving throw at disadvantage.

This spell ends after 10 minutes, or when it is cast again. You may use an action to extinguish the magical flames.

The magical flames ignite flammable objects in its area that aren’t being worn or carried.

The spell’s damage is increased when you reach 5th level(1d4), 11th level(2d4), and 17th level(3d4).