Crumple Zone

You exert your power of Gravity to crush the armor of your target. Target must make a Strength Saving Throw, on a fail ,the targets armor begins to crack and crumple, reducing the targets AC by 2 and movement speed is reduced by 15 ft for the duration.

On a success, the targets armor isn't damaged, however the gravitational force exerted still reduces their movement by 15 ft.