I'm behind on the manga so forgive me if parts of this have been done before.

For one reason or another Konoha is in grave danger. Remember how the 3rd hokkage was sealed with Oorchimaru's techniques? Only he can save the village so he uses a sound ninja and summons himself with Oorchimaru's zombie technique. After a few episodes his work is done and he takes his life (or unsummons himself) because he used a forbidden technique to reture to life and has no right to live.

Pretty cool huh?