Kuroki is dope indeed! His fight with Kanoh was the best ever.
Personally I liked Wakatsuki the most, Blast Core all the way. Hatsumi was cool too.
Not surprised you like Akoya, he's like Akainu in terms of ideology.
I guess you probably won't enjoy Omega if you fully read it though, kinda went the way of post TS OP...I'm desperately hoping they will lock in since we're in the final arc now.
But the spinoff Star Strike It Rich (with all female fighters) is great.
One fan also made a work called Convict Colloseum which is REALLY good.
Art is not on the same level ofc but is still decent and the story and characters are really fun. You should check it out if you have the time.