A scenario worthy of chapter 1000 but feels too soon for such a terrible wound to happen, unless Kaido can handle it now.
WB obviously with his busted heart.
BM's picture of Mother Caramel.
And now Kaido's scar.
WB didn't start taking any injury until after Squardo stabbed his heart. It was then further damaged with him having a heart attack mid-fight against Akainu. You know as well as I do how it goes from there.
By Jinbei's admission, the shock from damaging MC's picture was enough to make BM bled. Sadly, the alliance couldn't make use of that opportunity to further damage Big Mom thanks to her CoC.
I think of Kaido's scar in a similar manner. A9 attacked him sporadically and dealt many damages, which (unfortunately for them) healed completely. Since those include many stabbing wounds he received on the platform, there is no reason to believe his insides couldn't heal at all. This means, even with Luffy's Ryuo or Kidd's possible megazord or Law's Gamma Knife, any damage he takes is bound to heal in time and the alliance will have to start from 0 again (like A9 had to start all over again once Kaido returned to his human form). Having to fight 2 Yonkos alone put the alliance at an insurmountable disadvantage, let alone when one of them can heal endlessly. I feel like they would lose if this were the situation.
However, it's not like Kaido can heal instantly. The trick here is not only to give him an injury big enough for his healing factor to handle quickly, but also which leaves him open to be further damaged. The fact that Oden's attack left a scar alone means that either Kaido had no healing factor 20 years ago or his healing factor did not yet reach its current level.
I think of Kaido's old wound being reopened as his being stabbed by Squardo or MC picture being broken moment. The moment where his toughness start taking a dent for the alliance to jump on him. That's why it has to happen early in the fight.
And what a way it would be to end Chapter 1000, too!
:cheers::cheers::cheers: