I agree, Sentoumaru probably uses seastone punches to hit luffy. in addition to giant-like strength and all.

also, people have been complaining that Brooke doesn't get any chance to show his skills, since he is the weaker swordsman, seems like those times are ending.

I wonder if anyone else will go, maybe chopper (somebody will need to stop him now).

I think that Kuma sends them to a secret testing ground, where they are kept asleep in tubes for dr.vega crazy experiments.