Thunderous Bash

You build up a booming energy, releasing it as a punch. Make a melee spell attack against a creature you can reach. On a hit, the target takes 4d8 thunder damage and must make a strength saving throw. On a success, it is pushed 5 ft backwards and suffers no other ill effect. On a failure, the target is pushed back 20 ft, and if it collides with an object or a wall it and the target take 1d4 bludgeoning damage for every 5ft traveled. If the object or wall the target hits is reduced to 0 hit points, the target goes through the object, continuing backwards which can cause another collision.