Even worse are the fans who say she's been Defiled Forever by Femto raping her and she should've "gotten over it" like Guts. This falls flat on its face for several reasons. Guts was sold to a pedophile by his hateful foster father, which did traumatize him to the point where he had a panic attack after sleeping with her for the first time, but Casca was raped by the equivalent of Satan, after all of her comrades had been eaten alive, some of them trying to keep her alive. The evil power Femto was radiating at that point was enough to turn her unborn child into a mutant, so of course Casca reacts badly when she's touched after that. While the event reduced her to a Cute Mute and The Ophelia, you also have to take into account the kind of character Guts is - before Character Development, he was bloodthirsty, rude, used innocent bystanders as human shields, and abandoned Casca for a long period of time. Some fans call her weak or an idiot for running from Guts, even if he means well and is fighting off the demons who are after them both...but conveniently forget that his Enemy Within wants her dead, and is not above possessing Guts to achieve it.
Not to mention that one has to take into account that Casca's mind regressed into something that is almost animalistic. As degrading as it sounds, Casca doesn't think with logic and is really dependent on her instincts for survival, so when someone poses a clear and present threat to her, she reacts to protect herself, hence, the reason why she fears Guts for the time being.
One MORE thing. Remember the brand which signals a free human meal to every apostle in a ten-mile radius? Yeah, people tend to forget that that thing doesn't only bleed, it hurts - really, really, really, really, REALLY badly depending on how close you are to a power apostle. Guts is overflowing with raw power and muscle and he can just barely stand being in the presence of Femto at the beginning of the story. Now, let's get back to Casca, who was, in all actually, the closest ANYONE has physically been to a Godhand, the most powerful of the apostles. And this all happens when she is being held in place and raped in very horrific ways in front of a man she loves while at the same time being subjected to EXCRUCIATING PHYSICAL PAIN... needless to say: SHE CANNOT POSSIBLY BE ENJOYING THIS!!