Pffbt okay I ended up really liking most of what wall-market-whiskey-sours was thinking for Genesis, so I’m gunna post that ramble and then my own ramble. So lots of rambling under the cut.
wall-market-whiskey-sours:
Canon sum-up: Yes, Sephiroth, Genesis and Angeal are bros, but their friendship is kind of dysfunctional, mostly because Genesis is a spoiled brat who’s jealous of Sephiroth’s fame and hero-status (but for some reason I love him anyway).
MV Headcanon you are free to cherrypick pieces from or disregard entirely: Genesis attends RGU and runs in some of the same circles as Sephiroth, being from a wealthy family that is technically Jenovan (although mostly just around important holidays/when it’s convenient, as evidenced by how definitely not shiny Gen is). And idk maybe his family has donated a good sum of money to RGU’s science department, since in canon they’re affliated with Shinra. So his family’s got wealth and power enough to gain superficial respect, but not that Old Money Blue-Blood kind of respect the Crescents have.
Genesis is in drama or classics or literature, however you interpret his obsession with LOVELESS, and is, to steal a line from myself I’ve used before, that kid who has free use of his parents’ platinum card but shoplifts anyway. He’s overly dramatic, always attempting to steal the spotlight, always trying to one-up people.
He becomes “friends” with Sephiroth more as a challenge than anything else. Barnacles himself to Seph at any opportunity because he enjoys ruffling people’s feathers. Plus Sephiroth tends to be the center of attention wherever he goes, so if Genesis is attached to Seph (or better yet, has Sephiroth’s attention) then he’s the center of attention too.
So just flat-out disregarding Angeal, I’m interpreting this (hopefully correctly?) as them being a pair that’s like, “We became friends by accident and we kind of hate each other but it’s been too long and I’ve become accustomed to his presence, as obnoxious as it is.” With an undertone of like... a dignified villain and his more animated right-hand man.
I’m just picturing Seph talking to the camera like in a reality show, explaining how after he and Zack stopped being BFFs, Zack took up with dull, uncultured, barely-got-accepted-to-RGU Cloud from Boonie Island. Meanwhile Seph picked up Genesis, an old family friend who is better bred, has a better understanding of “how the world works” (read: “rich and the same religion as me”), and is very intellectual because he studies classic literature. But then Genesis comes into the background of the shot, doing something obnoxious. Seph hears him but just purses his lips and continues to stare into the camera.
Also the religion thing is kind of an interesting parallel/metaphor thing. Cuz I’d been thinking that Jenovanism these days is starting to split into the super orthodox, and the more relaxed/reformed. Orthodox Jenovans bag on reformed Jenovans all the time and consider them kind of disgraceful.... until someone of another religion entirely comes along. Seph really dislikes Genesis at times, but when faced with groups of people his dislikes even MORE, suddenly it’s all “oh, he’s with me.”