Demon Chen is the demonic monstrosity that Madam Chen morphs into at will. The demonic form of Madam Chen was unknown to most, with Mr. Lam presumably being the only exception. Demon Chen's wicked nature showed itself even in human form, as Madam Chen had a cruel if not sadistic personality known all too well by Hana.
- "I'm very impressed with your audacity, child. Or is it a lack of emotion masquerading as courage? Hmm, is that how you can kill so many, Mei Yun?"
- —Demon Chen to Hana
Madam Chen first morphs into her demonic form while waiting for Deke in her chambers. As Deke wanders in, she changes into her demonic form and slits his throat with her clawed limbs. Hana later runs into Madam Chen's room and finds her holding Deke's corpse. Madam Chen remembers Hana by her name Mei Yun and taunts her. Hana tells Madam Chen that she doesn't scare her, prompting Madam Chen to morph into her demon form before she throws Deke off a balcony and through a glass roof, impaling his head on a statue as he lands. Demon Chen then tells Hana that she was foolish to return as Hana runs out of the room. Demon Chen later finds Hana's clothes hanging in a changing room and laughs.
Demon Chen enters the brothel's meat locker and gets Hana's attention by turning on a rotating saw. She commends Hana for her audacity but questions if it is just her lack of emotion masquerading as courage. She asks Hana how she can kill so many and be without emotion, revealing that Hana had sex with Jin so he would help her escape the brothel, and that he wouldn't help unless she did so. Hana responds by calling Demon Chen a "bitch from hell" and Chen tells her to take solace in the fact that she was right before attacking her. Demon Chen surrounds herself in a forcefield and summons Demon Whores to attack Hana, but Hana uses paper figures in the shape of Madam Chen to put out the forcefield and revert her to human form. Hana shoots Demon Chen's vulnerable human form, fatally wounding her.
Demon Chen warns Hana that hell awaits the world once Wee Ming flowers into full potential. Angered at Chen calling her by the name Mei Yun, she takes the rotating saw and hacks apart Demon Chen's body. Demon Chen's body blows up the concrete underneath her, revealing a path down to Hell.Demon Chen is encountered in Hell, her body having been transported there after death. She is chained in place and gives Hana a doll, telling her that if she takes it to her daughter then she will give her something to help her when she returns. Hana finds a vision of herself as a child who she gives the doll to. Demon Chen gives Hana a tree branch for her assistance and asks Hana if she likes what she saw when she returns. Hana tells her that she is not her daughter and Demon Chen replies that she was once her girl "Mei Yun". Hana responds that Demon Chen killed Mei Yun and that her name is Hana. Demon Chen tells Hana that nothing was taken from her that she was not willing to give, and that she only fools herself by believing differently. Upon saying this, Demon Chen's body evaporates and three Demon Monks take her place and attack Hana.
Demon Chen is much taller than her human form, with gray scaly skin and two large mounds on her torso that look like like demon breasts. Her arms are long, narrow and end in sharp claws that can easily decapitate a person.