Unstable Fireball

A bright streak flashes from you to a point you choose within range and then blossoms with a low roar into a fiery explosion. Each creature in a 20-foot-radius Sphere centered on that point makes a Dexterity saving throw, taking 10d20 Fire damage and 10d10 necrotic on a failed save or half as much damage on a successful one. After the blast any creature in the blast radius will take 10d10 necrotic upon entering or starting their turn in the area. This effect lasts for 1 hour.

Flammable objects in the area that aren’t being worn or carried start burning.