Warning: contains spoilers for Choujin X
Rize's small but pivotal role in Tokyo Ghoul was quite memorable, which is why it's unsurprising that series creator Sui Ishida is bringing a similar character into his new manga, Choujin X.
In Tokyo Ghoul, Rize is the reason why protagonist Ken Kaneki partially transforms into one of the manga's eponymous monsters. Not in a good way either. Rize lures him to his supposed death under the pretext of a date (and that she's human) when, in reality, she's a ghoul and wants to feast on his flesh. Luckily for him, she fails spectacularly. Ken survives (though he's left in critical condition) and Rize dies. Ken's only hope of survival, however, is contingent on him receiving an immediate organ transplant. Since Rize is already dead and has organs, the doctors decided to use hers . But this procedure causes Ken to become a half-ghoul, acquiring these monsters' voracious appetite for humans and growing their predatory organ called a kagune.
Ishida's ostensible reinterpretation of Rize appears much later in Choujin X than in Tokyo Ghoul. For one thing, the manga's protagonist, Tokio Kurohara, has already acquired his newfound powers as a Choujin when he has the misfortune of meeting her. Tokio's face now looks like some sort of vulture-like mask and he's unable to revert back to a state where he doesn't possess avian facial qualities. This is problematic because Tokio doesn't want his identity as a Choujin to be discovered. His only hope is to rely on one of his strange powers that allows him to understand and communicate with birds. Since he resembles a vulture, Tokio thinks he needs to speak with one, and, luckily, he remembers that the local zoo keeps such a bird.
Upon his arrival at the zoo in chapter four of Choujin X, Tokio discovers that the establishment recently closed, though the animals have yet to be removed. While he fails to find an employee who can help him, there just so happens to be a beautiful woman watching him closely who then does the unthinkable; she randomly begins engaging Tokio in conversation. It, therefore, doesn't take long before she convinces him to break into the zoo with her. After they arrive at the vulture's cage, the girl begins flirting with Tokio shamelessly before she escalates the situation suddenly by transforming into a giant serpent and closes her massive serpentine jaws around his head. After such an incredibly unexpected and unfortunate turn of events for the manga's hero, Tokio somehow finds the will and strength to free his head from her deadly maw before the snake-like Choujin decides to play a sick, sadistic game with him.
Although this mysterious woman isn't the reason why Tokio acquires his newfound power and transformation in Choujin X, it's impossible not to recognize the fact that she uses her feminine wiles to seduce Tokio in an attempt to eat him just like Rize does with Ken in Tokyo Ghoul. For the sake of mangaka Sui Ishida, he hopefully decided to create another Rize-like character due to the original's popularity instead of finding inspiration from personal experience with a cold-hearted woman. Regardless, it's clear that she already plays a much larger role in Ishida's latest manga as opposed to Rize who died almost immediately in Tokyo Ghoul. Unless she's suddenly killed, it appears as though this snake-like Choujin is here to stay for the long haul. Tokio obviously doesn't need her organs to become a Choujin, that's for sure.