Why can't Kenpachi cut Crona? 'cus i don't see that black blood stopping Ken-chan. The Kendo move would cut Crona in half(heck even his normal slash withou eyepatch would cut trough) Even if by some mircale the black blood can take the attack Krona would be sent flying and would get hurt from the impact.
Because black blood can block all physical attacks
Also black blood can catch her as she falls...
I think Chrona (from the manga) would win easily enough...
As she's way more powerful in the manga