If I was making an Overwatch-esque fighting game I'd have an interaction mechanic that changes based on the characters relationship. The simplest version of this would be like, a proximity stun effect with a cooldown that plays a unique voice line depending on the pair-up, but the more ambitious version would have 3 different effects;
Threaten, which gives a damage boost and/or increased crit chance to the attacker
Plead, which gives you a decrease in damage, or possibly some kind of armour.
and Flirt, which would be the stun.
This would give a strategic advantage for players who know the lore, as well as being a way to characterize both individual characters and their relationships. Like, if you have a character who usually Pleads, the one guy they Threaten says a lot about them. And two characters having different interactions (as in, A Flirts with B but B Threatens A) tells you a lot about where they're at - and gives players an interesting challenge, where they can theoretically cancel out/counter each others interactions if they know what they're doing and can get the timing right. You could also potentially change interactions if you have an evolving story, and use that as a way to rebalance the game.
This would probably be hard to balance in the first place and might difficult on an esport level but I just think it'd be neat.
Also if I was making an Overwatch-esque fighting game the premise would be that assassination was made legal, but since regular murder is still a crime assassins have to be, like, super obvious about it. People start wearing costumes and adopting stupid gimmicks so it's obvious at a glance that they are doing a Perfectly Legal Killing and not a murder + people won't clock them and freak out when they're just buying groceries with they're blood money.
Obviously public figures start upping their securities and it turns out the people most willing to fight weirdos in costumes are other weirdos in costumes. So characters can be on either the Assassin or Guard team for any match up without it being weird because this is just everyone's day job, but behind the scenes there's interpersonal drama and maybe some political intrigue going on. Mostly drama though.
I was actually gonna draw a bunch of fighting game OC's a while back but then I got Way Too Deep into rendering the first character and never went back to my other sketches. Anyways here's a character I call The Clown Car.
[ID: A digital illustration of a polka-dotted clown car with a face and comically elevated suspension. Three clowns are popping out; Sorry Face (they/them), a purple and yellow clown in a dress shirt and tie, is hanging out of the right side window with a shotgun; Silly Face (he/him) A red and blue clown in a tutu and suspenders, is popping out of the roof on a spring loaded platform with a tommygun; Scary Face (it/its), a green and orange clown with puffy shorts, arm socks, and a bikini top is lying down on the left door, which has lowered like a drawbridge, holding a revolver. End ID]
The Clown Car counts as one character and every time you attack a different clown pops out. I can't decide if it's funnier for it to be high damage and high skill floor so all the serious gamers Git Good at it or if it should be the easiest newbie friendly character so tons of The Clown Cars are rolling around every match.
(also yes I was playing a lot of Balatro at the time. whatever)

















