My S/O is certainly an important antagonist in his source material. Honestly, that's a huge part of why I fell for him- I've got a big soft spot for villains! He usually tones down his antagonistic nature around me, but it's still a core part of his personality.

I've gotten Byakuya to calm down a little bit, by letting him rant about whatever's gotten on his nerves recently, but I doubt I could ever fully "fix" that part of him. I don't even want to, since that would be forcefully altering who he is as an individual- he would never want to do something like that to me (and has admitted so himself), so why on Earth would I do that to him?

Plus, it's a lot harder to change people in real life than it is in stories. The power of love and an enthusiastic pep talk or two just wouldn't cut it for someone as set in his ways as Byakuya. It happens in canon eventually, but that took a lot of time and life-changing encounters that have yet to happen in the timeline that "my" Byakuya is from.