The blinding spell is like the lighting and healing spell combined. It is placed either in the clan castle and set a timer and place to set it or use it by making a new defense. when attacking you can use it by placing it on a certain area and the defense will either get confused and spin around (like the cannon) or they will shoot there own buildings! If you are using it in a clan castle troops attacking will walk around not attacking confused outside but in range of the defenses!
Let me know if this helps



