Dark Exchange

You touch an injured, willing creature, concentrate on the wound as the sinew magically stitches close wounds, graft overs burns and otherwise closes and protects the injured creature. Heal up to 2d8+Mod Hit Points up to the character's maximum hit points AND reduce their maximum Hit Points by half the amount healed (round down). If as a result of this spell the character's current Hit Points would exceed their new maximum Hit Points adjust the current Hit Points to the new maximum. The lost maximum Hit Points recover after a long rest. 

This spell cannot heal undead.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the healing increases by 1d8 for each slot level above 1st.