Doing something a little different here, if I may... 12 and 28 for Parker (Leverage) and Wilson (House)
ooo good questions and good characters this is gonna take a second.
12. What's a headcanon you have for this character?
parker is agender but she's also decided not to care about it. womanhood is something she puts on to grift; femininity is a tool when she wants to use it and a puzzle she pokes at half-heartedly when she doesn't. she's not unaware that something's different about her relationship to gender, but she thinks it's one of her parker-isms. to find out there are lots of other people like her would delight her to no end. let's steal a pride parade.
28. If you could have this character meet another in another media, who would you have them meet?
leverage x jonathan creek crossover. let parker push jonathan off a building in one of her rigs. let her lose him in the vents. let jonathan teach her how to solve a closed-room mystery.
12. What's a headcanon you have for this character?
i'm gonna throw out the obvious 'he survives for a very long time both to his and house's amazement and it pisses them off lowkey bc they blew up their lives for their big gay roadtrip for nothing' because it's obvious and not fun and also blatant wish fulfillment from me, the guy who doesn't like it when people die.
wilson was an extremely lonely child. he had friends, but he was no one's best friend unless he was their shoulder to cry on when they'd had a fight with someone higher on their personal hierarchy.
it made house's almost instant obsession with him addicting. even when house was happy, he stuck to wilson like a burr. when he was miserable, it was more and worse, like wilson was as necessary as the vicodin and the cane. it was frustrating and overwhelming, but wilson's fucked-up psyche gorged on it.
28. If you could have this character meet another in another media, who would you have them meet?
sorry im trash im throwing him together with tv!bertie wooster.
he should like bertie! bertie is Literally Nice. but he sees the physical simililarities to house, sees bertie being clueless and easy to manipulate, and needs to take care of him, and decides he hates him SOOO quickly.
and it holds a mirror up to himself that he hates even more! that he's petty and bitter that taking care of someone who needs it has made him loathe them, but he's full on "bitch eating crackers" about everything bertie does, and it drives him insane, wanting to understand why it's making him so mad, wanting to Fix Himself. being overly nice to bertie to make up for it, and bertie is fucking clueless, jimmy's his new best friend, don't you know.
and it's that bertie looks like house but is antithetical to everything house is. he's gullible, affable, kind, pushes to forgive in hours what house would hold onto for a lifetime. and it's seeing down the line of knowing that if he had to take care of bertie, he'd have burnout in Weeks because he Can't let bertie be... bertie.
meanwhile, presumably in a different pocket universe, house and jeeves are subtly circling each other like vicious cats, arching and growling while they both pretend that's Not what they're doing.