Immediately from the title, I’m thinking this is a Sasuke!B-side of the Never Lookin’ To Come Back ‘verse. Like, what kind of shit has he gone through after his planet was destroyed? And then growing up as part of the Organization and going on black op missions up until he winds up on the Shuumatsu…
Sasuke’s moral compass is not exactly one for giving up, clearly. It may not always guide him in the right direction, but it at least makes him keep going. Which… I mean, was a disaster in canon, but can be a good thing so long as someone else points him in the right direction.
This is where Kakashi would show up in this ‘verse. As the one who “rescued” Sasuke by putting him in the Organization (so that Danzo couldn’t get him) he’d feature prominently in Sasuke’s past–whether as himself or as Agent Wolf–and maybe he’s the one who runs interference between ROOT and Shuumatsu the more they get involved with the politics of Senju vs Danzo.
I wonder what Sasuke’s opinion on the Shuumatsu crew is. Even before Neji and Hinata show up, that is–though the Hyuuga chancellor’s missing daughter and her first cousin is pretty interesting. Like, he definitely knows that Shino–the nameless Teacher of the Will of Fire–is the grandson of the Aburame chancellor. He probably knows that Shikako Heijo is in fact Shikako Nara, the Nara moon minister’s daughter. He probably also knows that–while the Inuzuka have been hit hard by the war–Kiba is the alpha’s son.
… I don’t think he knows about Naruto mostly because NOBODY is supposed to know about Naruto. (Except, you know, Kakashi and Jiraiya, probably)… and I don’t know if I want to go with my once-considered idea of TenTen actually being Danzo’s granddaughter via a disowned/runaway child but Sasuke definitely doesn’t know that, either.
The point is, Sasuke knows many secrets about the crew that they don’t necessarily know about each other and he lives in their starboard shuttle enjoying the entertainment. Obviously, he helps out when it’s needed, but he doesn’t volunteer his aid. Given his own adolescence of watching masked people return to The Org’s HQ and make jokes about assassinating people or disclosing their for various crimes, Sasuke finds the shenanigans the Shuumatsu crew get up to absolutely hilarious.
Of course, once the Hyuuga cousins show up and Ino points them in the direction of Tsunade, it starts to get much less fun. He’s not going to bail–the reason for which has less to do with him getting the Shuumatsu as his official mission, and more to do with how he’s actually fond of the crew–but now he’s got to defend the closest thing to home he’s had since ROOT destroyed his planet.