Cure Undead

You can choose to sacrifice some of your own HP to heal an Undead Creature or bring them back to consciousness.   You touch the creature and cast the spell.  The creature heals 1d8 plus your spell casting modifier, and you lose the same amount of HP.  You must also succeed on a DC10 Constitution Saving Throw, or your maximum HP is reduced by the same amount. This reduction lasts until you finish a long rest. If this effect reduces you hit point maximum to 0 you fall unconscious.

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