emergency cover

as an action or reaction create a 10 by 10 feet translucent wall of magic that cannot be walked through with 1d6 + your proficiency modifier health points. This wall can block any attack damage except force or psychic; receiving the damage instead, if the wall takes more damage than its health points do a constitution saving throw DC 10 or half the remaining damage (whichever higher) to take half the damage remaining on a successful save, all of it on a fail. if the caster receives damage  regular concentration rules apply 

At higher spell levels add 1d6 to the health per spell level.