Okay, hang with me for a few minutes. This one is a bit of a wild one with several degrees of separation from the current timeline, because... I have issues. I swear it is vaguely interesting/worth it and makes sense, somewhat.
So: Bastille is the reincarnation of three souls. Pollutedsoul is one of those souls. Pollie himself is the reincarnation of a tom from ages ago. Like, decades. Anyway, this unnamed tom used to live in this big fancy house with his family, and he was absolutely in love with this girl. Like, love of his life, soulmate, he would die for her. He also had an older brother who was better than him in every way and was favored by their parents. I think you can see where this is going, and you right! Older bro gets the girl. Younger bro is pretty fucked in the head, withers away in ago, forgotten in the shadows of everyone basking in the exciting glory that is new love. Anyway, after some time he loses it, locks everyone in the house, murders his whole family, sobs and asks this girl to love him, and when she's -- understandably -- horrifying, he kills her and then kills himself.
So, enter Pollutedsoul. Pollie grew up with these superimposed images of the past fucking up his vision, so he knew he was a reincarnation and not just schizophrenic (eventually). He was also mildly disturbed by these weird dreams he had, but he never remembered what they were. He was also unaware of the whole, ya-know, murdering everyone thing. He spent his entire life feeling like he was missing something, though -- like we was looking for something/someone. Eventually he determined that it must be someone, but he didn't know who, only that they were out there... somewhere. Spoiler alert: it's the soul of his reincarnated love. Ta-da!
Anyway, Pollie died without ever accomplishing his own achievable plot point. Sad! So, since Bast is the character of tying up loose ends and making all these angry souls feel rest, that means Bast is fated to complete that task for Pollie. So, that's where your homie comes in: I want Bast to finally meet that long lost soul.
Obviously, they will not suddenly fall in love and have babies. Bastille will remember what Pollutedsoul didn't, and basically just get to apologize for the sins of his like thrice-reincarnated fuckery. There may be some soul searching. He may feel like he's actually accomplished something after achieving what Pollie couldn't. Whatever.
What I need: Basically, anything. Your character can be the actual reincarnation of her and you can carry on your merry way with this backstory for her and plot accordingly. They can be homies or just meet the once and vow to stay hella far away. You do you. Or! She could just be, like, a partial reincarnation. Or a ghost. Or she can possess your character. I understand possibly not wanting to create an entire new character for this minor plot point, so I'm flexible with making shit work if this sort of soul business sounds even remotely interesting.
So sha'know hmu with comments, questions, concerns, ideas.