Crystal Ward

The caster squeezes the items in their hands as the spectral crystal ward forms. It grows to 12ft in width and 8ft in height. The spell acts as a wall where everyone behind the caster will have their ac act two points higher to ranged/magical attacks. And melee attacks must best the con save of the caster. And at character level eight the spell becomes 14 ft width and 10ft height. But now the con of the caster counts one point higher.