Considering the technique didn't exist a couple days ago, I doubt Tsunade is qualified to to rate it as anything when Naruto hasn't even had a chance to try and work the kinks out of the technique yet.


I also thought it was pretty funny that they have the corpse of a guy who could make himself immortal and use multiple hearts and the only information they are getting from his corpse is "what Naruto did to him".

Tsunade should be discovering the secret of heart transplant surgery now.