Chilling Blade

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails. On a hit, the target suffers the attack’s normal effects, and is partially encased in strands of ice and frost until the start of your next turn. The target's movement speed is reduced by 10 feet, and if it uses its reaction to make an attack of opportunity, it immediately takes 1d8 cold damage, and the spell ends.

This spell's damage increases when you reach higher levels. At 5th level, the melee attack deals an extra 1d8 cold damage to the target, and the damage it takes for making an attack of opportunity increases to 2d8. Both damage rolls increase by 1d8 at 11th level and 17th level.