Fujitora is 100% going after Vivi, so She is gonna be his Momo/Koby/Bonney
Not sure which Adv. CoC User gonna stop Fuji though
As for Akainu, i'm pretty sure He will try to stop Kuja Pirates from entering New World
And this Sub-Plot's Young Gen Character gonna be Marguerite
As for Akainu's Fight, it's gonna be against Rayleigh imo (It's time to see his Signature Attack)
Could be. Morgans and Wapol are at least not enough so it would have to be one of these three. BB should be least likely after taking out Law + his crew taking out Garp.
1 Mihawk (swordsman vs swordsman)
2 Blackbeard (gravity vs darkness/gravity)
3 Garland (swordsman vs swordsman, WG opposer vs WG top dog)
Akainu > Rayleigh is clear as day. At best Rayleigh could take an arm. I suppose it would give Luffy even more reason to hate Akainu, not as if he needs it. If you want to make Akainu shine then yeah, Rayleigh could be a great hype tool.