Divine Spite

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects and then becomes sheathed in holy white energy until the start of your next turn. If the target willingly makes an attack against a target other than you before then, the target takes 1d6 radiant damage, and the spell ends. If the target is undead, it must roll 1d4 and subtract the number rolled from the attack roll.

At 5th level, the melee attack deals an extra 1d6 radiant damage to the target on a hit, and the damage the target takes for attacking increases to 2d6. Both damage rolls increase by 1d6 at 11th level (2d6 and 3d6) and again at 17th level (3d6 and 4d6).