Arhai’s Infinite Recursion

Pure destructive energy flows from your hand to one willing creature that you can touch. The next time that creature casts a spell that deals damage of any kind using a spell slot of 1st level or higher, reroll any damage die that landed on a 1. You take 1d4 necrotic damage and the spell deals an additional 1d6 radiant or necrotic damage (your choice) for every damage die rerolled this way. Additional rolls of 1 continue to trigger this effect.

If no 1s are rolled on any of the damage die for the spell that would be affected, this spell affects the next damaging spell you cast instead.