Roman Torchwick being the next Ozpin in Fixing RWBY is a decision that Celtic Phoenix made purely to satisfy his own ego. Roman was one of his favorite characters and he saw Oscar as a blank slate so he acts all smug and superior about how much better this is than canon. Celtic does not put in the work to make Roman joining the main cast believable, and Roman is everything that RWBY stands against
In canon Roman stuck with Cinder's side because he knows that he's by far the weakest person in their dynamic, and how Salem's faction is going to change the world. He posits himself as a "realist" when he starts ranting about the "real world" being a cold cruel place, and how Ruby should just hurry up and die "like every other huntsman in history." He's not doing this for any particular reason other than to save his own skin
He's by far the most pathetic person working with Salem's faction. Everyone else there believes in something which is why they're there. Cinder sees following Salem as the best path to the power she craves. Emerald sees Cinder as family and follows the one person who gave her any sort of comfort in life. Mercury lived an abusive life of violence and sees no other way to continue. Hazel seeks revenge against Ozpin and has been so radicalized that he can rationalize himself attacking Nora and Oscar as Oz's sins. Tyrian views Salem as his goddess that embodies destruction and wants to see her end the world. Even Watts who has the pettiest reason of all is doing this because he feels like his genius was unappreciated by Ironwood. Neo if you count her seeks revenge for Roman's death, first against Cinder, and then Ruby when she realizes Cinder's far too strong for her to handle
Roman doesn't have any of that. He's a crook that got wrapped up in something far bigger than himself, and he's too much of a coward to even flee for fear of retaliation. He just wants a comfortable spot on the "winning side." The only person working for Salem who you could consider as pathetic as Roman is Lionheart who teamed up with her to save his own skin
RWBY is a series that sides with those who can stand up to their fears. Those that don't get punished or villainized by the narrative
Roman died in the middle of his big speech to Ruby. Lionheart betrayed his kingdom out of fear of Salem and pathetically died by her hands begging for his life. Raven loses Vernal and any relationships she has with her team and family. Ironwood's paranoia consumes him leaving him to die completely alone on Atlas rather than the people of Mantle he abandoned
Roman explaining his motivation in Fixing RWBY was retained exactly the same as canon. According to Celtic it was perfect so it didn't require any changes. This creates problems with him being the next Ozpin
He doesn't change to explain him joining the main cast. There's no overcoming his fears, no desire to fix his mistakes, he joins up with RNJR and Qrow because Oz keeps pestering him to the point that he can't even sleep until he agrees. Yeah. Sure. Go ahead. Act out of character to make the canon story happen. Fuck off Celtic
Rather understandably RNJR attack him on sight in V5, but once he reveals that Oz is in him they all accept him as part of the group. Nobody meaningfully confronts Roman on the fact that he tried to kill Ruby and was their enemy for the Beacon era other than Blake, his inclusion is so forced. They just put up with him as if this is normal now. Due to Oscar being a new face and decidedly not a criminal that tried to kill Ruby or helped in the Fall of Beacon, his inclusion to the main cast without much questioning fits a hell of a lot better
Roman doesn't grow to become a more heroic person either, at least not by much. He's still a conman thief that literally steals his way into the Argus train's deluxe car, and he's overjoyed at Ruby suggesting to steal a Bullhead in V6 because she's growing up so fast. He clashes so hard with the rest of the main cast, he's only a "hero" in the sense that he's working with them now instead of Cinder. I know it's the point for him to clash given his origins as a villain in canon but fuck that point
When Dragon Ball did this with Vegeta, he came closer to the heroes' values over time. By the Cell arc he starts training just like the others, he stops taking shortcuts to power because those methods are hollow. Imagine if Vegeta was still planning to become immortal and was purely abusing his body's zenkais by the Cell games to get stronger, only now he's supposed to be with the heroes. That's Roman in FRWBY
When Oz stops yapping in his head after The Lost Fable Roman leaves at Argus because Oz shutting up is what he wanted all along, he's made that clear since V5. The only reason he rejoins the main cast is because Neo thinks sticking with them is their best shot at getting Oz out of him, something she's determined to do
Celtic kept the similar soul rule for Oz's reincarnation, which means he had to be rewritten to be in Roman
RWBY is a series that explores heroism in a lot of angles, and in this discussion Oz in canon was the classical heroic knight. He saved Salem from her father's tower for no other reason than it being the right thing to do, just like the fairy tail heroes Ruby loves. No ulterior motives, no scheming, just simple uncomplicated heroics. In FRWBY, Oz is outright stated by Jinn to be "more cunning than brave," which completely destroys the classical heroics angle and him embodying the heroes Ruby admired
Throughout FRWBY's runtime we're given hints of Oz being a much worse person than canon. Raven says that Oz is just keeping the world the way he likes it rather than actually fighting for anything to improve it. When Roman's plan to trick Lionheart with a disguise Neo makes fails, Leo gets furious when it breaks because Oz will "do anything to take any petty advantage possible"
In canon Oz kept his secrets out of necessity because of Salem's immortality being a pretty strong hope crusher. He couldn't see a way to defeat her and knew if he ever summoned the gods they would wipe out humanity, so his hand was forced to drag this out as long as he has. In FRWBY him hiding the truth comes across as trying to bury his own much worse past than canon from the world. On top fo this his mission from the gods is too unclear for anybody in or out of universe to make out, and he only kept the war with Salem going because if the gods were called he was certain she would die
Roman is antithetical to the values that RWBY champions, and due to Oz's FRWBY rewrites so is he. He's a cynical, cowardly, purely selfish, conman criminal that tried to kill the main cast on numerous occasions, who tries to position himself as the "realist" compared to Ruby. And he hasn't grown to overcome any of his flaws either. You want to know the funny thing though? They fit right in with FRWBY. A series with a more cynical tone trying so hard to be smarter and more pragmatic than canon RWBY, rewriting an asshole and villain like Roman to be part of the main cast, and makes Oz far more villainous than canon? Yeah. I can believe it. It slots in pretty naturally. Big shame this completely runs counter to canon RWBY's themes
Honestly I'm rooting for Melanie to kill Roman. I want this asshole off the screen and out of that main character slot, and she's fully justified in targeting him for her revenge given his role in the Fall of Beacon and her sister's resulting death. Honestly if she does successfully kill Roman I'd applaud Celtic for having the balls to do so. But I know that he won't
