Xingzi is a man of an above average height. He sports black spiky hair, long enough to cover his forehead, as well as his left eye that is hidden by an eyepatch. However, the hair on his back is long enough to be kept in a pony tail, reaching all the way to the lower part of his body. His attire is military or sports-like, wearing dark colored jacket and trousers with stripes. He also keeps several small bags on himself, most likely containing an equipment necessary for his job.
Xingzi has shown to possess a ruthless personality, not hesitating to kill the residents of the slums for the sake of his job. Upon meeting Karin, he was seen smiling when interacting with her and was shown to be excited when witnessing the ability of her Immortality first hand. He also continued expressing an enjoyment during their battle, especially when having an upper hand. Xingzi later revealed that he's been in love with Karin and has been searching for her ever since finding out that she was alive. He stated the desire to "break her heart" so eternity wouldn't be so bad anymore and he would love her forever. However, his feelings aren't met with an appropriate response.
Xingzi appears for the first time, looking over the New Tokyo Slums as Kaito joins him and Nagumo after his brief training of Touta Konoe. Xingzi notes that it's time for work and asks whether it is okay to kill all the residents as the three of them ready to start their job.
Xingzi is then seen in the slums, approaching Karin who is taking a shower. He attempts to shoot her with his pistol, destroying her barrier. However, Karin manages to take the gun and tries to use it against her opponent, but Xingzi deflects the bullet with his Naba High Frequency Blade. While Karin worries about the situation outside, Xingzi states that he thought the skills of Immortals become dull after achieving Immortality and proceeds claiming that he will get the taste of Karin's immortality, calling her "The Saintess of Steel". The two then engage in combat, with Xingzi deflecting another bullet and cutting through Karin's arm with his knife. He is excited to see that in spite of his attacks landing, there are no scars on Karin's body. At that moment, Karin delivers a devastating punch, throwing Xingzi onto the opposite wall. Holding him, Karin notices that he's just a human and tells him to leave. However, Xingzi takes advantage of this, grabbing his pistol and shooting Karin into her mouth. Noticing that in spite of her Immortality, Karin still can feel pain, Xingzi introduces herself, revealing his true purpose.
They continue their battle, with Xingzi further testing Karin's Immortality. He comes to the conclusion that hold techniques will be most effective and even though Karin attempts to crash him into the wall, Xingzi traps her with his Shadow Magic. He reveals himself to be an actual Magic user and also the one controlling the Shadow Puppets rampaging in the town. Xingzi then proceeds stabbing Karin with his blade, further showing off her Immortality and calling it "the work of a god". He reveals the knowledge of her past and the fact that he's been searching for her ever since he found out that she was still alive. Xingzi then mocks her for acting this way even though she was treated badly in the past and proceeds claiming that he loves her, wanting to "break her heart" so having an unbreakable body won't be so bad anymore.
However, Karin manages to kick Xingzi into his crotch and while he wonders how she undid the Shadow Magic, Karin begins glowing with a light that Xingzi recognizes to be Nimbus Holy Light. Unable to understand this, Xingzi asks how it is possible as Karin was supposed to be cursed, however, Karin states that the source of her despair is love. She begins attacking him while commenting on how she knows that it is hypocrisy, but she will do what she wants to do. Xingzi is then hit by Holy Fist, followed by another barrage of attacks. Lying on the ground, he is told by Karin to die as he makes her sick for being the highest class pervert she's ever met.
At the base of the space elevator, Xingzi appears one more time, attempting to assassinate Kirie Sakurame. He manages to succeed six times, however, after Kirie returns in time yet again and Touta Konoe becomes aware of the situation, Xingzi's final attempt to attack Kirie is thwarted and Touta defeats the assassin.
Shadow Magic: Xingzi has described himself to be a traditional Magic user that can control Shadow Spirits. He was shown to be able to use this Magic as a hold technique to create multiple shadow hands in order to capture Karin. The hands completely envelop the target's body with an intention to render any movement to be impossible. However, Karin was able to break free with the use of her Nimbus Holy Light.
- Shadow Puppets: Xingzi has shown an ability to summon puppets that he can either fully control or set them to automatically perform a certain action. The amount of puppets he can summon can reach hundreds.
- Naba High Frequency Blade: Xingzi has been shown to be quite efficient in the usage of this special blade. He effortlessly deflected several bullets that Karin had shot at him, as well as use it against her in combat. Xingzi has commended this weapon as it is able to cut much better than everything else, according to his own words. Based on an Indonesian knive called Karambit.
- Japanese: Ryōta Ōsaka
- English: Alejandro Saab