User blog comment:AYET/Let's Discuss Chapter 733/@comment-24285649-20131226153022

I don't think that 'Kaido', in disguise, attacked the contestents, rendering them unconscious/beaten. The fact that there was no one left standing, hence, the attacker receiving collateral suggests that it was someone strong but not near yonko level.

Would Whitebeard/Blackbeard/Shanks have fallen after combat with a few contestants below Luffy's level of power? I think not.

However, this is assuming that the attacker is the one who is now getting up.