we know madra said he kept a few secrets from itachi which may be conserning the ms sharingan. the ability to put out the amaterasu could been one of them could be the reason he suvive the attack itachi implanted in sasuke maybe itachi didn't get taught this from maddra. they may be other secrets to the ms sharingan we haven't seen yet that maddra probrobly used to become the most powerful of the clan. what do u guys think?