TLDR: I think that both Trimax and Tristamp Knives are still attached to her, in their own ways.
‼️ Spoilers for Trigun Maximum ‼️
Oh man, do I have THOUGHTS.
One thing that stood out to me upon reading the manga was obviously the glaring difference between Trimax Nai & Stampede Nai’s behaviour during childhood. Trimax Nai was very sensitive and constantly looking for reassurance, hopeful and warm and just a pleasure to be around and have in your life, it seems: textbook definition of a smol cinnamon roll. Unlike his Stampede counterpart, he seems to be pretty much identical to Vash in terms of power and maintenance: he eats, he sleeps, there is no emphasis on how Vash cannot generate anything while Knives can. I am certain this has been pointed out before, but Trimax Nai behaves a lot like Stampede Vash in my opinion. Trimax Nai was loyal to a fault and the discovery of Tesla’s remains were so jarring to him, he passed out for several days. I think what was worst for Trimax Nai was not necessarily the discovery that: hey, there was someone just like us on this ship before, but she was severely mistreated and left in literal shreds, it was that Rem (and Conrad) knew about this and let it happen, were possibly even participants in the experiments; where he once harboured nothing but love and admiration for the woman who raised him, there was now doubt. And fear. Unlike Vash, he had loved humans and studied them extensively. He had their entire history at his disposal and his tiny, doubt-filled child-mind was left alone to draw its conclusions: about how humans always repeat the same patterns, how they never learn from their mistakes, at least not long-term. Rem had kept Tesla a secret, so who is to tell him that she does not have ulterior motives in mind? Trimax Nai already knew that Rem has tried to keep their existence a secret. When he played around with the engines and caused the crew to be woken from cryosleep, Rem made them hide in their rooms - to keep them secret, and safe yes, but to a scared child, couldn’t this also be misinterpreted in hindsight as an attempt to keep them a secret for her own selfish goals? The thing that slowly but surely killed Nai’s trust and affection for Rem was doubt. He has always been a sensitive child, a tiny boy with lots of emotions and when he notices his brother doesn’t share his views, doesn’t listen to him, doesn’t even try to understand him? He retreats into himself, and his thoughts echo around his head, growing ever louder and louder until they crescendo in one last desperate act, one last chance for Rem to show that she is true and genuine and he can trust her love: Nai causes the ship to crash. But see, this is where he miscalculated. You cannot tell me that prior to his slow descent into madness, Nai would not have stayed behind and tried to save humanity; he had lived humanity and wanted so desperately to be accepted by them, to live by their side. Rem had been the one to sow those seeds, she had been the one to teach him compassion and love. So, as the ship was doomed to crash, Nai waited for Rem to make her choice: come with them, live by their side as their mother, she had claimed to love them, after all, had said that she would take care of them. If she chose to come with them, he could trust her. But we all knew which choice Rem made and this was the second breach of trust, the final evidence that Nai needed to know for certain that Rem’s love was not true enough. She chose humanity over her sons. She left her boys to fend for themselves while she saved humanity - while she saved Tesla’s tormentors - and Nai understood it had always just been him and Vash against the rest of the world. There was no one else like them. Humans had made sure of that. But he is wrong yet again, because while he has had time to prepare himself for the loss of his mother (and it probably still hurt, to have his assumptions proven correct), Vash was robbed of his mother figure. His wound is still fresh and deep and unlike Nai who had bottled everything up and made his peace, he had put his grievances aside, had picked up and nursed hope when Nai had dropped it.
Nai had taught him to love humanity and Rem had made it easy for him to do so, but the tender brother he once had was slowly rotting from inside out while his mother had been burnt to a crisp out of his reach. Vash had lost everything that night, though he still clung to the memory of his brother for a couple more decades. Eventually it had become too much to bear and he ran from Knives, kickstarting once more his brother’s hatred for mankind that had not quite lain dormant so much as it had been “eased” by the certainty of Vash’s presence in his life. Humanity had not been wiped from No Man’s Land, but at the very least he could be certain that they had each other and they were safe. But then Vash left him. Vash just straight up looked him in the eyes when he asked him to wait up and went into some stranger’s car and drove off, leaving Knives behind in the desert, alone once more, well and truly alone this time. He had no one else to blame but himself, but self-reflection is a bitter pill to swallow and it is easier to blame others: Rem had taught Vash to love humans, so it must be Rem’s fault that Vash is choosing them over his own brother, right?
I think one of the main limitations of Trimax when it comes to understanding Knives is that the story is not told with him as the protagonist in mind. We mostly see Knives through the eyes of others (there are exceptions, of course, especially later on in Trimax as Knives merges with his sisters and controls the hive mind), so most flashbacks we see of him are coloured in whichever flavour the person witnessing him associated with that memory: we see Nai’s kindness and ambition through Vash’s eyes, but also his sudden coldness, the way he followed Vash like a lost puppy that doesn’t know yet that its presence is no longer welcome and comforting. We see him rise from the womb of one of his sisters like a monster. We see him slaughter and lay to waste an entire village under the empty gaze of Legato, a ruthless killer, a knight in shining armour, a reason to keep on going in a world that has only ever been cruel to him. We also see Knives struggle, in moments when he is well and truly by himself: when he sees memories of his sisters, when he realizes that Vash is no longer the brother he once had, that he needs to be killed for his plans to succeed. We see him falter, when Vash rescues him. We see him regain purpose, becoming a protector once more as he carrie’s Vash to safety, as he *begs for help*. We see him, humbled and grateful. We see him choose death, not full of anger and hate but at peace. He gives his life in exchange for a blessing. He lets go of his agenda. He learns to trust again. He trusts in Vash. He trusts in humanity. He trusts, once more, in Rem’s words, Rem’s actions. And I ask you, OP, who was it that taught Knives to be a guardian? Who taught him to fight until the bitter end for what he thought was the right thing to do? Who showed him how to shoulder the burden of being a protector of his kind even though that burden might one day become his downfall? I don’t think that Knives ever fully let go of Rem, not even in his darkest hours.
There are some things that go deeper than fear, hate, ignorance. There are some things that stay with us every step of the way, no matter how far we stray from out starting point. Knives turned his back on humanity, but whether he knew it or not, he chose to follow in Rem’s footsteps, however misguided, however twisted, he became a little child’s idea of a protective caretaker. And at the very end, when the plants desert him and he is left with nothing but his brother and some humans who, despite everything, choose to listen to him and save his brother, the only thing he has left, the only thing he ever allowed himself to mourn losing, I think that Knives rediscovers that spark he once had, that warmth and caring that Vash had remembered even decades after Knives had become a monster to him. I think that, at the end, Knives becomes a little more of the boy he once was. The boy that loved Rem, that loved humanity, that wanted nothing more than to be accepted as a friend. And knowing fully well that he is beyond redemption, he chooses to use what little is left of him to leave a lasting impression upon one human. A good impression. It is the last he will ever make, so he will have to make it count. And I imagine that the genuine wonder, the awe, the sparkle in the boys eyes? That it was enough. That he felt accepted. That he was at peace when he left, forever.
Knives’ attachment to Rem always lingered. It was just buried too deep.
So. Stampede Knives. His is a very different story, because while Trimax Knives has always had an interest in living among humans, Stampede Knives seems to have resigned himself to an existence apart from humanity at a very young age. Remember that Trimax Knives chose isolation. I think that Stampede Knives was not that lucky.
Right from the very beginning, the twins’ lives in Stampede are very different from Trimax: Knives is entirely self-sufficient, powerful, the perfect organism, while Vash is not. Vash devours and rests and produces nothing. If it weren’t for the markings on his skin, he would easily pass as a human. Knives is different. He does not need food, he likely needs little to no rest, he can influence the world around him to his whims. His greatest fault is being without flaw, from an outsider’s perspective. We see him as a quiet, curious boy, someone who does not know how to relax properly even in the presence of his mother figure, someone who keeps his cards close to his chest. As a parent, it is often hard to divide your time between your children equally. As a parent of one self-sufficient child and one child that is entirely reliant on your nurturing care, I imagine that Rem - possibly without even meaning to - has always devoted more time and energy to Vash. Remember, Knives is the sensitive child, the one yearning for approval and affection. In an environment where he is taught that someone else’s needs are more important, constantly? I think that smol cinnamon roll all but shriveled up and died, hiding behind a veneer of carefully calculated distance and only breaking through in moments Knives deemed appropriate, when others’ needs weren’t more pressing than his own. From the very start, Knives is taught that he is stronger than Vash, and he sees that Vash is entirely dependent on someone else; on Rem. I think that at that young age Knives lacked the proper emotional maturity to express his sadness upon being excluded as Vash’s most important person (Vash is dependent on Rem, not his brother) as well as not being Rem’s most loved son - twice the amount of rejection for the low price of hitting the genetic jackpot.
I think that even before Tesla, Knives started to blame Rem for the way he felt, not knowing who else to blame for the way he always felt alienated, especially because Rem, no doubt unintentionally, poured gasoline on the flickering flame of resentment growing ever stronger in Nai’s chest: forcing Knives to act like something he is not by making him eat food he doesn’t want to eat, scolding him for making Vash feel inferior when his pride in his self-sufficient is quite literally all he has left, it is, after all, what he is reduced to so often. It’s not easy being someone’s idea of perfect when you really just want to be a little boy getting your family’s attention and care, I imagine. Knives already cannot relate to Vash and Rem on an incredibly fundamental level because he does not understand and share their needs and it certainly didn’t help to be constantly forced to pretend to be something he is not when he is not truly allowed to enjoy the same amount of care and affection that Vash gets.
Tesla happens, once again Nai’s trust falters, only this time he is already somewhat lonely, somewhat angry, somewhat sad and all that unexpressed and untapped emotion that he had kept bottled up but unnamed? He puts her name to it. Rem tries to explain, but he has already understood, has already made up his mind: Tesla was too alien, too different and they could not understand her. So they destroyed her. And much like Trimax Knives Tristamp Knives spent a lot of time studying humans and couldn’t find it in himself to trust them. He was convinced they would eventually reject them and hurt them, hurt Vash who was weaker than him, who was dependent and too afraid of being left alone to even consider that Rem or others might hurt him.
But all was not lost yet. He still held on to Rem, he still believed her to be an exception, possibly, maybe, hopefully, if only for Vash’s sake. Knives offers her his hand, an implicit invitation to come along, to care for Vash like she had always done, like she had claimed brought her so much pleasure. He is doubtful. And as Rem chooses humanity over them? He had loved her and craved her love so much once, but as they leave and Vash cries, he is left silent, pondering. He is used to being pushed aside. Vash is not. He knows this pain. The ships crash, but his victory feels hollow: his mother is a liar, his brother is hurting, his family is falling apart and even through the wreckage and anger Knives is still just a little child who keeps living in other people’s shadows. Something else is always more important than him. He never gets what he wants. Even with Rem gone, Vash is still out of his reach, running away as he is slowly succumbing to insanity, facing the reality that he failed in the worst possible way: humanity lives, Rem dies. This is not what was supposed to happen. They should have been alone, the three of them. He would have provided for them. He would have let Rem live out her life beside them, without threat, to make Vash happy, maybe to make himself happy as well.
But Knives doesn’t get nice things. All he gets is mistakes and wreckage. But he is patient. He has been taught to wait his turn all his life. And when Vash returns, he is so full of hope, so desperate for Vash to see and understand him. So desperate for connection. But yet again someone else is more important, yet again he is pushed aside by the single most important person in his life. He is forced to hurt Vash in order not to lose him; and yet he still loses him. Vash has chosen and Knives is left to make sense of it. And the only way he can make sense of it is by stripping Vash of his agency, by telling himself that it was all Rem’s fault. That humanity had poisoned his brother’s mind.
Knives keeps seeing Rem’s ghost around every corner where Vash is concerned. She is no longer around, but she haunts him. She personifies his ultimate failure: his failure at being just a little more human-like, his failure to understand Vash, his failure to be as worthy of love and attention as others, his failure to keep her alive, his failure to make Vash happy, his failure to keep Vash by his side, his failure to eradicate mankind, his failure to keep Vash from harm. Rem had never been perfect to Knives but he had loved her once, in spite of it. Guess when they called him self-sufficient they had forgotten to take into account his need for connection. Knives is lonely and Knives is desperate and his grief is a blade sharper than any knife he can create.
It must have been like a slap to his face when, after a century and a half, he finally had a shot at getting his brother back, however twisted and hollowed out he had to make him, only for Vash to reject him in favour of Rem once again. He knew that Rem was a source of comfort for Vash, that she was the key to his affection. But when Knives tried to tie that affection to himself, her ghost struck once more and Vash slips right through his fingers.
Knives hates Rem. But before that, he loved her. Until she betrayed him. But the again, isn’t hate the flip side of affection? Stampede Knives is still attached to her, she is the beginning and the end of his woes. I think he wishes fervently to cut himself loose and leave her behind, but as long as Vash does not choose to be beside him, he cannot let go of her as well.