Put him in FCW for the love of God. Debut a new darker mask or something like that to go with the new name(Since they're having copyright issues apparently.)
They need written permission from Sin Cara to get the name trademarked. Truely this is an impossible thing to do
and realistically, they can't just shove him in FCW . That ship's sailed, and they've invested too much in "Sin Cara" to just throw it away. He'll be back in a month without too much hooha and start feuding with Sheamus.