That’s my secret, anon…
…I’m always freaking out.
About those skins, anyway. I love them to death. As for your question, in my personal AU for demon hunter sombra and monster hunter mccree, they don’t really work as a team due to the nature of what they hunt (though they used to be partners in the past). When they do decide to team up again, I’d like to think that they’d go after something that both have had trouble catching – maybe like a powerful demon or an ancient vampire. Reason being, they can’t do it alone…but together they might have a chance. And they might strike a deal – sort of like, ‘I scratch your back and you scratch mine’ so they can both claim their respective bounties.
But after the jobs are done, they had all intent to separate again. McCree makes a comment that Sombra’s skills have improved and he’s mighty impressed. She makes a similar comment for someone who merely hunts monsters. Even after all their years apart, their rivalry is strong but they still have an amicable relationship. He suggests that maybe staying together wouldn’t be such a bad idea – simply to hunt and get bounties, of course. Sombra isn’t really sure at first…but doesn’t deny the logic behind his suggestion. Eventually she agrees and they hunt together as a team.
If you meant like one of the other Overwatch characters as their ‘Halloween’ counterparts as the ‘who’ in your question, then I’d guess they’d go after the Countess first. She’s not as big a threat or as mythical as some of the other ‘monsters’ floating around out there. She’s very much real and just as deadly. Her bounty is also rather handsome, giving them further incentive to hunt her down.