Eh i play magic and from what is seen the most OP of them would probably have to be Nanashi's. Also you should have made them planeswalkers. Those are basically the hero OP AS HELL cards. Otherwise they are just normal cards really.
OK Doug, just saying, but planeswalkers are fine and all...but in the end it's still the creatures that rly make the difference. Mostly the legendaries and to be fair, not just any shinobi can be a planeswalker, now can they xD
not to mention many of the legendary creatures ended up becoming planeswalkers in the series (ex. Karn, Nicol bolas)