Terra Force

You have learned to convert your own life energy into fuel for this spell. You condense your energy into a sphere between your hands. You may then choose to take anywhere from 1d10 to 10d10 necrotic damage. A target must succeed on a DEX saving throw. The target then takes 3d6 fire damage and 3d6 radiant damage, or half as much on a successful save. On a failed save, they are pushed back 10 feet and are knocked prone.  

For every additional 1d10 necrotic damage you take, it increases the radius of the sphere by 5 feet to a maximum of 30 feet. Also, you increase the fire damage and radiant damage by 1d6 to a maximum of 12d6 damage. If any target within the radius of the sphere fails its saving throw, they are thrown back 10 feet and are knocked prone.

The fire spreads around corners. It ignites flammable objects in the area that aren't being worn or carried. The area affected by this spell then glows, creating a source of light for 30 feet.

If the necrotic damage drops you to zero hit points, the caster remains concious until after damage is dealt, then immediately falls unconscious.