Tbf Big Mom having a bones broke by a metal bull make no sense
I mean the attack is clearly not as strong as Hakai or as strong as WB’s quake punch but it broke her bones
That means that Big Mom would be destroyed beyond recognition if she try to block Hakai of if WB attack her
Kidd and Law just show that under her haki (which magically disappear apparently…) she has less durability than any top 5 supernovas