Vander's Barrier

You target one creature that is a huge creature or smaller within range and a bluish, transparent, cubic barrier forms around them. the creature must make a Dex saving through. On a success nothing happens and the spell ends, on a fail the creature is trapped in a barrier that just fits its size. other creatures around them cannot be caught and are pushed aside to make room. 

The barrier is considered a construct with an AC equal to your spell save and HP of 30. the creature on the inside and creatures on the outside may attempt to attack and break the barrier. Once it reaches zero HP the barrier shatters and disappears.

When casting at higher levels the barrier gains 15  extra HP per spell slot used above 3rd level.