If you know Shunsui from Bleach and the story of his Bankai, what inspired it, its the same story that inspired Green Bull's tattoo and character and it's gonna very dark, tragic and make him appear in a whole new "shade" or light, really add depth to him.
Him and Fujitora are kind of kindred spirits in I'm certain just like Fujitora has a blatantly dark and tragic backstory, so does Green Bull and it's affected their outlooks on life and thus personalities and why they chose to enlist in the Marines, become Admirals and thus their chosen brands of Justice, what they believe in.
Green Bull fighting Fujitora even paralleled Akainu fighting Kuzan and we know Green Bull is a HUGE Akainu fanboy ofc, he is implied to be even more relentless than Akainu, more driven and we've seen glimpses of it (although he gave up too easily vs Shanks and his wifi haki nonsense disappointingly) and a bull is more savage, relentless and dangerous than a dog ever will be of course. Unless Akainu goes all Hell Hound/Cerberus on us of course lmao.
Some people even say Green Bull is more like "Suicidal Justice" or you could say "Kamikaze Justice" especially ofc and thus would be extremely fitting and badass too, so driven to getting justice, taking absolute justice to the absolute extreme where he is willing to die for his beliefs as I expected Akainu to be exactly, is perfect writing for Green Bull, a man who cannot die easily due to his devil fruit, surviving for years without eating and instantly regrowing himself from a mere plant shoot after Momonosuke blasted his entire being from existence with that Boro Breath too.
He is a "Bull" in every sense of the word, relentless, hot headed, brutal, terrifying, driven and thus also has to deal with "Bullshit" as well as having his own ofc lmao.
This is all headcanon/assumptions generally anyway ofc, but I have high expectations for Green Bull (which Oda will inevitably ruin as I never learn too) and Oda is gonna drop some bombshell about Green Bull and his mysterious black blade and why he won't use it and why Oda won't allow any information on or confirmation for it too.
He even gave Fujitora a supreme blade recently and Fujitora was exiled from the Marines temporarily by Akainu after their argument and his actions on Dressrosa AND Kuzan left the Marines after fighting Akainu to death (but Akainu spared him ofc) and thus Kuzan was exiled by Akainu or went on a self imposed permanent exile from the Marines too (unless he's undercover too).
This might be all nonsense on my part ofc, but that black blade shit is intentional I'm sure and Oda is cooking something big for Green Bull, even if Oda makes them look bad with feats and fights, he values them deeply as chararacter as we saw with Kizaru and Kuzan lately and thus Akainu too and we will see more with Fujitora soon finally too.
Oda bases the Admirals on his favourite actors, he's not gonna slouch with their writing as characters and he hasn't so far, except maybe keeping Akainu stuck to a desk. But he's still muh better than the worlds worst criminal (that worst part is truly fitting ironically) Dragon and Oda will deliver with all Admirals and thus Akainu in time I am certain regardless. Zephyr's writing in Film Z was fucking amazing and the highlight of the series and thus Kuzan and Kizaru too, especially Kuzan so I have VERY high hopes.
I believe he is cooking something with Smoker too in due time, smoking something big even.
Also I think that new black horse guy is based on a famous Japanese actor IIRC too, plus hes a coloured Zodiac too, he might end up replacing Kizaru in the near future for all we know? Whether Kizaru is demoted/exiled from the Marines for some reason or worse, killed by Blackbeard and his crew at some point or even executed by the the World Government.