Zoro was the star this chapter, though. Ever since the fighting began, Zoro has been on fire, particularly on defense. There were several instances where his teammates would’ve been dead or seriously injured without his intervention, and he has covered for them while dishing out his own form of offense at times. This chapter, he successfully defends against what is likely the strongest attack seen in the series, and continues to aid everyone despite his injuries.
Zoro’s block temporarily completely halted the momentum of the slash as it is a travelling attack that travels for Kilometers just like it did for Dorry and Brogy.
But when Zoro stops the attack we see this shockwave:
Then this triggers the reaction out of Big Mom and Kaido saying “WHAT”
Then obviously Zoro holds the attack for several seconds..He has enough time to yell things out..give everyone times to escape etc..This all couldn’t have happened in just one second.
But even if it is one second, for Zoro to even stop momentum of that attack temporarily, his defensive power must be 80 or 90% of the power of the attack.
Because think of it that way, if an object is moving with force of 500 pounds..an object that weighs 450 pounds would halt its momentum but an object weighing say 250 pounds would be pushed back without providing any resitance.
Another example of it would be me maximizing Bench at 225 pounds..I can do one rep..but I can easily completely 10 rep set of 195 pounds.
Zoro not getting launched literally means he at least has EMPEROR LEVEL PHYSICAL STRENGTH AND DEFENSE because he halted momentum of 2 times emperor level attack.
*Theory by ShishioIsBack
