Despite the lack of any blood relation, Charles has always been the big brother figure in her life, and Raven even refers to him as such. However, it might be more apt to refer to Charles as a father figure. In comparison to herself, she regards him as both wise and stuffy behind his years, often affectionately referring to him as an "old fart" or labeling his thesis as tedious, revealing a bit of a disparity between the two of them in terms of maturity. After escaping from her parents, two individuals so disappointed in her mutation that they had attempted to take her life instead, and living on the streets due to both fear and rejection, she happened upon the home of a little boy — nearly the same age — who quickly accepted her into his home and life. With no parental guidance, Charles is the one who assumed that mantle and stepped in to instruct, protect, and care for her. Charles is more of a guardian than a brother while Raven is more of a ward than a sister; he's educated her on several subjects after her refusal to attend school, lectured her on numerous occasions only to be met with several exasperated eye rolls fitting of any rebellious daughter, has placed a roof over her head, and has continuously sheltered her.

Charles is, more or less, a protector in Raven's life — which is, as the cliche goes, both a blessing and a curse for her. He welcomed her into his life when no other would and the two quickly became each other's only friend — and she's quite annoyed at anyone who tries to take him away, too, hence her decision to sabotage his attempts to flirt with random girls. Although she might act as a typical sister would in that sense, Charles has still always been there for her, nearly from the very beginning, making him a monumental influence on her life and decisions. Not any little boy could convince his parents to take in a stranger, but it stands to reason that Charles utilized his own abilities to be able to persuade his mother into thinking little of it. Even at a young age, he protects her from the cold streets and abandonment by accepting her presence, reassuring her that she will have as much food as she pleases and will no longer have to steal to survive. Over time, the protection she receives from him expands to Charles cleaning up each of her mishaps and messes as she learns to harness her abilities. Though he chides her for purposely revealing her yellow eyes while he's attempting to chat up a pretty girl in a pub, he informs her that a big mistake on her part does not bear thinking about, implying that he would willingly alter the minds of the other patrons to keep her hidden if her concentration happened to slip. As Raven states that he knows she has difficulty controlling her mutation from time to time and Charles' offer to protect her secret should it inadvertently come to light, it stands to reason that it isn't the first instance in which Charles has performed such a feat in order to protect her.

In a way, that's precisely why Raven's views on mutants are quite limited, and why she comes across as naive and sheltered in some of her interactions. While he accepts her as a friend, he does not wholly embrace her mutation. He warns her against revealing herself, becoming vexed when she happens to do so in the bar or when she struts around the abode in her true form without her robe on at a later point, which insinuates that her mutation is not necessarily a good thing, and Raven has merely learned to keep her identity a secret from the world at large due to Charles' instructions. Their mutations and shared history are what tie them together, but Raven's fear of rejection and Charles' insistence upon keeping her mutation hidden are what prevent her from fully exposing herself to society. As Charles is the only fellow mutant she's ever encountered, her views on remaining concealed and sheltered gradually change once she's introduced to her teammates.

While she's enamoured with the abilities of the others, Hank is the one who she relates to most, and, save for Erik, he's likely the biggest factor into pushing her toward embracing herself and Erik's philosophy. She sees pieces of herself within him, to an extent. Hank, just like her, possesses a mutation that's also physical — and, just like her, he attempts to keep it concealed (but to a lesser extent than Raven, as Hank's mutation has merely altered his feet) as best as he possibly can out of fear of being bullied. As a result of his own self-loathing, he wishes to use her blood as a potential way of concocting a cure that will strip them of their physical mutations while keeping their abilities intact. Raven, still accustomed to hiding at this point, readily agrees to it — but after Erik's words resonate with her — you want society to accept you but you can't even accept yourself — and after admiring the unique traits of her teammates, she decides against it. After all, who's to say she won't come to accept herself if she can so readily embrace others? For the first time, she thinks that being unique is a beautiful thing and what sets them apart from others, and they shouldn't have to discard that side of themselves to fit in and be normal. She comes to believe society should accept them, not the other way around, but it's an ideology Hank disagrees with.

In the end, she doesn't inject herself with the cure. After facing the harshness of Hank's words, it's Erik she seeks out. While Erik plays a large role in influencing Raven to become more confident and self-assured with her image, herself, and her mutation by bluntly complimenting her until she has no choice but to become speechless at his blatant honesty rather than argue against him, he also piques Raven's interest romantically. After initially believing that no man would ever view her in such a way if she were to appear blue during the beginning of the movie, as she quizzes Charles to whether he would date her in her true form and faces Hank's cruel implication that she is less beautiful in her natural form, Erik quickly squanders that line of thinking. She tries to seduce him as she would any other man, at first, going through a series of different appearances in an attempt to appeal to him — but, like usual, he catches her off-guard when he states that he prefers the real Raven. Once he tells her she no longer needs to cover herself up, both literally and figuratively speaking, the two share an intimate moment — and though there's an understandable attraction there, it isn't their chemistry that causes the rift between herself and Charles.

That rift has, in a way, always been there — but it took a few pushes in a certain direction from Erik for Raven to ever truly realize it. It's safe to say that Erik's own philosophies begin to resonate within her. In contrast to the composed and peaceful Charles, Erik is more like Raven. He's more reckless, more impulsive, and holds more resentment toward the world for what has been done to him. As Raven implies earlier in the film, Charles doesn't know how it feels to be rejected from the world as she does. His mutation is invisible. Unlike her, he has nothing to run from, and before the government betrayed them after they had successfully stopped Shaw, he had never been betrayed by anyone as she has. Erik and Raven click with one another not only due to Erik forcefully reminding her that she is beautiful and strong in her uniqueness, but also due to the fact that they're both angry individuals who have, time and time again, come to realize that mutants will never be embraced by mankind.

When Raven lashes out at Charles once he tells her to cover herself up, it isn't solely at him — it's at his ideology. For years, he has encouraged her to keep herself hidden rather than encourage her to walk around as freely as she pleases, and only after she starts becoming swayed to Erik's side does she see that Charles is more concerned with inserting himself into the world as it is instead of taking her hand and turning against it and all of its ideals (which, in a way, feels as though it's a betrayal, as he chooses the world instead of her). Charles still has a hope for society, believing they can find a way to co-exist through peaceful negotiations — but both Erik and Raven have been burned one too many times to ever be as optimistic as Charles. Whereas Charles is forever that kind of optimist, Raven and Erik are both cynics. Erik fears the annihilation of mutantkind at the hands of humans and, after experiencing her parents' attempts to murder her and the government's betrayal, Raven comes to realize that Erik's line of thought is far more realistic than Charles' bright hope for peace between mankind and mutants — a feat which is, in Raven's mind, nearly impossible to achieve.

But as Charles has always been the constant in her life, she outwardly struggles to simply let him go. It isn't out of any inner conflict between the two men's differing philosophies, not anymore; it's more of a concern for Charles and the state he's in, as the worry is clear in her eyes as she looks at him. She even ignores Erik's outstretched hand at first — perhaps out of rejection for his part in Charles' accidental paralysis, or in part due to her inability to just let Charles go that easily — to approach her brother with tears in her eyes, but it's Charles that notices her hesitation to leave the one individual she's always had in her life and nudges her into accept Erik's offering, telling her that he knows it's what she wants. She's still teary-eyed as she does as Charles suggests — but she knows that, despite everything, Charles' ideology is not one she can willingly follow, nor a belief Charles will ever change. Charles has always been there to protect her, but in his attempts to watch over her, he has only sheltered her — and it's time for the world to see her for who she is, for her to grow up and spread her wings and do as she wants rather than as society, or even Charles, dictates.

With the rift between Raven and Charles expanding even further due to their opposing views and the mounting argumentativeness emerging between them, Erik represents the freedom that she's needed all along, and is her best shot at achieving what she desires: confidence, a place where she feels she truly belongs, and protection from a world she has never completely belonged to.