I think their last conversation in BCtu sort of opens a door that they’re going to speak to each and work things out. Canonically, that’s all the information we get. We also never explicitly get information about like, what exactly is wrong between them presently. We know that

they had a big fight at the end of TVA but that they calmed down

Armand has been afraid of Marius because he's scared that Marius doesn't still love him like he used to

in ROA Marius said he had the savage & ignorant soul of a child.

I always assume there's just 500 years of tension and conversations they've avoided, but we also never get a confirmation that they HAVEN'T had these conversations off screen anyway. So canonically, all we know is that they just had a traumatic experience and want to talk to each other.

Also canonically, they’re making another attempt at Vampire Commune and we don’t have an answer of like, will it stick this time, will it dissolve like Night Island, is it sustainable AT ALL to have a small group of the elite making rules and holding dominion over an entire culture???????? Reader’s choice lol.

But it leaves a question of like, what does returning to each other look like in this setup—they’re in touch now, they can find each other, they have cell phones, Armand can come and go at the Château as needed, Marius has a room at Trinity Gate, etc. Their relationship is civil and functional at this point. And does “returning” mean to be exclusive companions and to fuck off? Will Marius leave Court? Will Armand come and stay more often?  Idk ! 

These are questions that have 100 different answers because it’s all headcanon, but, what we know by the end of the series is that they’ve gone through something traumatic and Armand and Marius are going to talk to each other. What is that conversation about? What is the result? We don’t know. Armand is letting his FEELINGS THE FUCK OUT in this book as if he's had therapy, and Marius says he thinks Armand is ready to open his heart, if that gives us any clues! But does opening his heart mean "I am feeling vulnerable and brave to tell you how I feel because I almost lost you" or "I'm gonna read you the fuckin riot act because I did that to Lestat as well" ? lol Either way the thing here is that it's ARMAND'S decision and not about whether or not Marius left him in the past.

I think something that often goes overlooked in character discussions is their inherent inhumanity, and I really dislike the “thEyRe MonStErs” easy out of a lot of analyses, because it’s more than that. The entire purpose of the series and the reason the series was unique is that built a world where they’re MORE THAN. It’s not about simply being a monster—there’s nothing simple about it. And not being human doesn’t mean it’s all negative and all evil. What it means is that it’s Extra. They feel things on such a deeper level than we do, their brains function differently, and they’re immortal. They have all the time in the world to forgive each other when they want to, and they’re social creatures who want companions! The older you are, the scarier it is! It’s horror! Like even Marius’s relationship with Mael is so fucking special because like, as much as they put each other off, it’s like, someone they each still have, that’s been constant, and the world would look so different without them.

It just reminded me of this line in Six Feet Under (sorry I’m obsessed, I think everything always comes back to SFU for me LOL) but when Brenda says she used to think as she got older that she’d have more people in her life and that the opposite was true. So anyway for Marius like, regardless of if we want to get into selfish/selfless, Armand is one of the most important people in his life, and has been around for a quarter of Marius’s life, and nothing would be the same if Armand wasn’t around. 

And without the distraction of The Parents in the modern age I wonder if he’s like especially fragile and traumatized about losing people? Is he still traumatized by losing Pandora? And losing Armand the first time? It’s great that they have cell phones and a community now so no one gets too far from each other, but gosh.  

I don’t know what returning to each other looks like, as far as where canon left. Like, does the Château collapse? Is Daniel with them? Asking if Marius wants it is like, yeah maybe he would want Armand around Court more for moral support. And maybe if he decides to step away, and get space, maybe he would want Armand there with him as a safe place to land. When the Court inevitably collapses, will he want someone around? 

In the past, Marius tended to isolate himself in times of stress; is he still like that? Has the loss of The Parents changed this for him? Will Daniel and Armand allow him to isolate? Idk ! !!! 

But anyway sorry I’m rambling but my point about not being human and about being Extra is that there are a lot of parts in the series where vampires have a relationship or forgive each other even after they’ve deeply hurt each other or committed atrocities. Louis and Armand come to mind, so do Louis and Lestat, David and Lestat, Pandora and Santino. Even Marius calming down enough to be in his situationship with Avicus and sorta metamour to Mael. They are not human, they are capable of forgiveness. There are atrocities that humans are capable of never forgiving because we don’t have time to get over it. How can we even know how much time it takes to heal a grudge if we don’t live long enough to test it?

Even knowing that, 500 years still wasn’t enough to forgive Santino for what he did to them. Like sure if we wanna dunk on Marius and remind ourselves that he’s an arrogant self-centered jerk sometimes, and we could say that he’s mad at Santino for what he did to MARIUS—it’s not just the ego this time. He took Armand. He separated Marius and Armand. He destroyed their home. And even if they cooperated a few times in the 20th century, by the time B&G happens, he's been able to read TVA and knows what happened, what Santino did to him, what he did to the boys. (Like, did Marius read TVA? Did Armand ever tell him this privately? We don't know! But we do know that this is now been published for EVERYONE to read which is probably re-traumatizing for everyone involved and now everyone knows hajkgsdl)

So anyway, like. I know this has kinda been a non-answer because we’re talking about stuff that didn’t happen in canon and everything past BCtu is going to be our own headcanons. But I can say: Yes, Marius loves Armand deeply, and vampires are capable of incredible levels of empathy and forgiveness for each other, because their lives are too long and bleak and painful not to.

As to the idea that Marius left him in the past, personally I don’t agree! 

Marius not rescuing Armand from the cult is often misunderstood in fandom, but I could see why someone would point to that as a clue that Marius has left him in the past. It’s not that simple, though. Marius is too injured to save him, doesn’t even know if he’s alive,  and by the time he finally finds Armand he finds the cult situation too complicated to navigate. Don’t forget that Marius has pretty severe religious trauma, and is one of the characters who was turned against his will. By a cult!!! So to see Armand thriving with a cult is so triggering and disappointing, and I don’t think he’s strong enough to risk being rejected if he goes to rescue Armand only to learn he no longer wishes to be rescued. 

I would say that’s very unlike leaving him in the past, it’s more like seeing him as another one that got away. 

And then when they reunite in QOTD it’s during another extremely traumatic event in Marius’s life—we don’t know details about how everyone left Night Island or where everyone went, but what we DO know is that Marius lost The Parents—>Armand attempts suicide about a decade later—>Marius commits the big B+S Fuckup shortly after learning Armand is okay—>Marius fucks off to Scandinavia with Daniel to lick his wounds because everyone’s mad at him. 

VC skips around a LOT, and there’s so much that we don’t learn about, so much that happens between books and off screen. Like, we don’t KNOW how Marius wound up with Daniel. We don’t know exactly how much longer he stuck around in New Orleans after TVA, we don’t know what he and Armand were gonna talk about in BCtu before the series ended. And that’s the enD oF IT THERE’S NOTHING ELSE!

Marius truly doesn’t leave anything in the past, that’s the thing about him.

He’s still traumatized by the way he was turned. He still tries to sculpt his identity around what his life was as a Roman. He committed to the burden of The Parents for 2000 years, even when he was overwhelmed and wished he could stop. He spends centuries painting Pandora’s face over and over and over when he can’t find her. He still thinks Mael is a bumbling redneck from the woods. He still wanted Santino killed, even when they’d been civil with each other in QOTD and up to TVA.

And in BCtu when he’s living at Court he’s like, trying to embrace himself, allowing himself to be a weirdo because he’s around his own kind now. HE QUITS PANTS, YOU KNOW WHAT? HE ALWAYS HATED PANTS, LET’S NOT. 

I think even as humans there are so many things that shape us forever, that we never really move past. Even when we leave something in the past, it shapes us, it allows us to leave it in the past. People and events in our lives carve into us, whether we like it or not!!! And part of the horror of immortality is that it goes on, and on, and on, and on, your physical body gets hard and cold and monstrous, more and more uncanny, physically impervious, but their BRAINS AND HEARTS ARE STILL TENDER!! 

So no, no, I really don’t think Marius ever left Armand in the past. I think he left him to the cult because he thought Armand wanted it, I also think he gave Armand space after a disastrous fuckup. When he goes to speak to him at the end, he says it like ARMAND is the one that’s ready. He’s waiting for Armand! Marius was there the whole time, ready to be called upon if someone needs him! He lives to serve!