Altair's Cold Fusion

You touch a creature or object you can reach. A blue glow engulfs them and a sigil appears at the location you touched, a creature makes a Constitution saving throw and an object other than adamantine automatically fails. Each round this spell is active the target takes 3d10 cold damage, at the end of a creatures turns they may make a Constitution saving throw ending the effect on a success.

If a creature or object is reduced to 0 hit points the body or object implodes and at the end of the spell’s duration it then explodes dealing 6d12 fire damage in a 15ft radius.

At Higher Levels When this spell is cast at a higher level the explosion deals 1d12 extra damage for each slot level over 6th.