And how much better is BB's endurance now compared to back then?
Law with one attack now can do more damage than any of Ace's attacks back then. Is that a fair indicator of how difficult the match has been? When BB hasnt even used a single Yami technique?
Mid diff already? Yea no.
I would say BB's endurance hasn't increased that much. Cause he survived getting Gura punched and naginata slashed from an enraged WB, and Sengoku's shockwaves too.
BB has always been an endurance monster.
So yes, BB getting more damaged from a single attack of Law's than anything Ace did shows that Law is doing better than Ace did. And you said Ace vs BB was a mid diff. So why not Law vs BB.
And as I said, Ace landed his most damaging attack that we saw, after BB used yami a few times on him and got him confused. So Law still has more than enough chances to land attacks, like Puncture Wille, that was even better than shock Wille.
So yeah. This fights currently a mid diff. And will end in a high-extreme diff. More high than extreme probably.