I'm not convinced Tsunade's serious until she summons that damn slug.
Srsly
Every fight we've ever seen her in, she's summoned the slug, except for this one.
If she summons that little turd, she'd be able to coordinate attacks without having to continuously regroup in concentrated areas, which would keep Madara wondering where the attacks are coming from.
Ooniki obviously has some tricks that we've not seen yet. So we'll see what happens. I'd be surprised if Ooniki lives through this fight though. He's the oldest and, frankly, the craziest of the Kages.
Mizukage better have some extra moves. She has two bloodline limits. Not one. Two. Both seem to involve fire, but she's been very limited, in that the most she does is blow hot kisses and control boiling mist. Very short ranged, and somewhat slow. Very passe at this point.
Raikage... he seems to only have taijutsu, which is kinda meh. He needs some extra bits.
If the five kages are going to get backup, I'm kind thinking it might be the eight tails. At least at this point.
B can resist Madara's Genjutsu, he has the tailed beast bomb for a nice mass destruction ranged attack, and he's excellent in close combat.
But if she doesnt when its all said and done, she was basically a waste of ink in naruto.
