Channel

You contort and twists the weave and concentrate it into your immediate vicinity, creating a pocket of instability around you. Starting at the beginning of your next turn, the first leveled spell you cast is enhanced, provided that this spell hasn't ended. The enhanced spell is considered to be upcasted by one additional level. After you cast a spell enhanced by channel, you then take 1d6 necrotic damage. This damage cannot be reduced or prevented by any means.

At Higher Level. When you cast this spell using a spell slot of 2nd level or higher, the additional upcast level increases by 1, and the damage you take increases by 1d6 for each level above the 1st level.