I HAD A THOUGHT ON THE SUBWAY YESTERDAY so imagine in volume 8 after Marrow decides he’s done working for magic fbi he gets a warrant out for his arrest and a similar situation to v7 arises. So he turns to the only people he knows he can trust; team rwby.
After some arguing and some ifs and buts they decide they need to work together. The Happy Huntresses are also there, because all of them are trying to figure out how to free Qrow and Robyn, who are going on trial. He gets along with them. Fiona especially, (since she’s a precious ball of sunshine who must be protected at all costs and if she gets hurt and or dies in v8 istfg) and also Weiss, because she has that sassy no-nonsense attitude that he puts on for show but like... for real. And he looks up to her. Weiss also starts caring for Marrow little by little, and eventually he starts opening up more and showing his playful, softer side without the fear of being ridiculed. They also bond by, y’know, fighting the endless hoards of grimm being yeeted at them by the hour.
So later in the volume when the prison heist is going down (not really sure how all of this would work out because Salem, but bare with me) they manage to free Robyn and Qrow, but Marrow gets arrested in the process. Then Weiss decides that Oh No, they are not putting her man behind bars for being a Good Person™️ so she sneaks back into the prison with the help of May (and perhapeth Winter???) to get him back out. And when they’re finally free Marrow’s all like “You saved me... How did you even manage that?” And Weiss just smiles and says “Well, someone once told me us Schnees are used to getting what we want.”
Aaaaaaaand then they smooch (mayhaps)
BONUS: Jacques’ cell is in the same corridor as Marrow’s and he sees Weiss and is all like “Ah my daughter! You’ve finally come for me!” And Weiss doesn’t even give him a look or anything she just. Walks past the bastard.