
:v Marcus should be with Jun, while Graham should be with Louisa. Louisa is her own person and shouldn't be pushed to a man her past 'self' used to know. Jun's body was preserved by Marcus btw so there are two bodies. Louisa's and Jun's.
If there's a way for 'past self' / Jun (who communicates with Louisa in their mindscape) to transfer her consciousness over there, I think there wouldn't be much of a problem. Somehow, in the raws, Louisa or Jun (?) managed to move to Jun's old body. Trippy, I know.

I swear... if this goes DMMD on me (aoba/ren/twin thing), I'm gonna flip. My prediction is that Marcus will probably move on to the after life or something close, and Graham/Louisa are gonna be canon. It makes absolutely no sense for Louisa to switch lovers out of the blue when the entire manga showed more interaction between Graham and Louisa, and we were only introduced to Marcus this late. I think we're near the last volume of the novel series.

Very true very true, but if he did that for himself, why would he feel the need to show her then? And when you say, "nobody FORCED him to act that way" I don't totally agree. Those people who tortured Jun in the past kinda did force him into that kind of state, so you can't say that he's acting out on his own. I never said the MC owe's him anything, I just want her to acknowledge that he's like that, and doing that kind of stuff because of her(Jun). I just wish she would show a little sympathy towards him. But since it seems (?) like you don't like Marcus with the (keyword) current MC, then that means you agree with me. I believe that he should be able to develop love with Jun.
I love Marcus, but I don't think the current MC suits him( ̄へ ̄)
I also feel like she should at least acknowledge that he did all that for her.