I heard that thing before, and yes, it is true that Edo Tensei Treasure drops Itachi Susano better, but that was before and not a thing anymore this days .. Today, all treasure except the GNW Treasure drops Itachi Susano at the same rate .. 1 to 2 fragments for every 60 or so pulls .. If you are a f2p player that who don't want to spend a dime on this game, hoping to recruit Itachi Susano for free then that's the only possible way for you to do, keep pulling in treasures that drops Itachi Susano frags, if you have enough or good savings of coupons then wait for the right event to drop your coupons, Dancing Capsules is one of the events that you may consider ..