Blood Charm

You attempt to charm a monster of any type you can see within range. It must make a Wisdom saving throw DC12 , and does so with advantage if you are fighting it. If it fails the saving throw, it is charmed by you until the spell ends or until you do anything harmful to it. The charmed creature regards you as a friendly acquaintance. When the spell ends, the creature knows it was charmed by you.

doing this makes the user take 2 damage or 1d4 damage they must succeed on a DC8 charisma saving throw if failed the target isn’t charmed and knows the user was trying to charm them 

blood mages always have this cantrip prepared