Curse of Sustentation

1st-level evocation

Casting Time: 1 reaction, which you take when you lose concentration on a spell due to taking damage

Range: 60 feet

Components: V, S

Duration: Instantaneous

You utter a curse and gesture at the creature that distracted you and caused you to lose concentration on your spell, drawing flames of ire into your lungs. You take 1d10 fire damage, and the target must succeed on a Constitution saving throw or take the same amount of fire damage. You then make another Constitution saving throw to maintain concentration on the spell that triggered this reaction, adding the damage result to the roll and using the original DC from the damage the target originally dealt to you. If the saving throw succeeds, you don’t lose concentration on that spell.

If the damage from this spell reduces you to 0 hit points, you fall unconscious but are stable.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage to you and the target increases by 1d10 for every two slot levels above 1st.