Tohort's Unending Devotion

You attempt to charm anything you desire, whether it be man, beast or object that you can see within range. It must make a Charisma Saving throw, and does so with disadvantage unless it is hostile to you or your companions. If it fails the saving throw, it is charmed by you until the spell ends or you break concentration and the creature takes 1d12 necrotic damage from heartbreak. The charmed creature is utterly devoted to you and will follow your every command in attempt to please you. When the spell ends, the creature knows it was charmed by you.

At Higher Levels.  When cast at a spell slot of 4th level or higher the creature takes an extra 1d12 damage when this spell ends.