You conjure a shield of shimmering silver magical force that hovers around you in your space.  The shield grants you half cover against creatures who are on the opposite side of it from you.  When you cast this spell, select a creature you can see that is currently hostile to you.  For the duration, the shield hovers between you and the selected creature, and when that creature would target you with an attack roll, you can change the target from you to the shield instead.  The shield is an object with AC 20, +0 to all saving throws, is immune to poison and psychic damage, and has resistance to all other damage. 

You must use your bonus action on each of your turns to maintain the spell.  When you do so, you can select a different creature to be the focus of the shield’s effects.  The shield is destroyed and the spell ends early if the shield takes more than 30 damage during a single turn, if it is hit by the Disintegrate spell, or if you use your bonus action to do anything other than maintain the spell.

At Higher Levels:  When cast using a higher level spell slot, the damage the shield can take during a turn before being destroyed increases by 5 for every slot level above 5.