Shokunokabe (色の壁, Lit. "Chromatic Wall")

this spell uses all the elements, like the Shokunokyu; and unlike the offensive version this spell continously draws energy from the elements around it, making it insuspectible to continous assault given that it will just restore itself over time; its only weakness is the fact that it can be destroyed by a single attack, whose power exceeds that of what it currently has: If used at the right time however, and if it is given enough time to strengthen itself its defense is in theory, unbreakable.