Elemental Shield

When you are hit with an attack, you call to the elements beneath you such as sand, snow, mud or similar element to protect you. A thin 6 foot tall wall of the available element rises in front of you, absorbing half of the damage. Then, you recieve the remaining damage, and the elemental shield collapeses, making the 5 by 5 foot space in front of you difficult terrain. A creature standing in that space must make a Dexterity saving throw. On a failed save, the creature must spend 15 feet of movement to exit the space, as the elements collapse over them. On a successful save, the creature manages to escape and moves 5 feet away in any direction available (creature's choice).