Challenger's Mark

You bellow out a magical challenge that your opponent finds difficult to ignore. When casting this spell, make a melee weapon attack against one creature within range. On a hit, the target suffers the attack’s normal effects. In addition, before the beginning of your next turn, the target has disadvantage on the next attack roll it makes that does not target you. Also, if the target willingly moves more than 30 feet away from you, or makes an attack that suffers disadvantage from this spell, it immediately takes 1d8 psychic damage.

This spell’s damage increases when you reach higher levels. At 5th level, the melee attack deals an extra 1d8 psychic damage to the target, and the damage the target suffers for moving more than 30 feet away from you, or making an attack that does not target you with disadvantage, increases to 2d8. Both damage rolls increase by 1d8 at 11th level and 17th level.