Shub

''“Don't worry. I mean no harm.”''Shub (슈브) was a well-mannered dimensional monster who was previously the secretary of Ash and Dust in the Nameless Legion. She holds the power of the Abyss Eyes which are capable of controlling other dimensional monsters but not humans. When her lover, Kaiger, is killed by Dust, Shub flees to the Closers to seek asylum, fearing that she would be next.

Story
Shub meets Bai and is taken aboard the Wheel of Fortune. The Closers are initially wary and call in Agent Celine who reads Shub's mind and concludes that Shub has no hostility towards the Closers. Shub provides information to the Closers such as a planned dimensional monster attack on Closers Division HQ which thus allows Bai to hunt them down beforehand. One of the monsters that Bai kills housed Kaiger's spirit, placed there by Dust to torment Shub as punishment for escaping the Legion.

Shub is pursued by Death Walkers, assassins of the Nameless legion after her face was seen by other dimensional monsters. Most notably, a death walker in a red hood known as the Red Death appears. The Red Death is powerful enough to overwhelm Bai, prompting Shub to assist Bai by using her Abyss Eyes to restrain it. With their combined efforts, they manage to drive off the Red Death.

Unbeknownst to her, Shub carries a parasite implanted by Dust to prevent her from leaking information about the identity of Ash and Dust. The parasite is eventually activated when Shub is questioned by Closers officals, taking control of her and transforming her into Shub Abyss. In this form, her legs are replaced by a Cobra-like snake. Shub Abyss then proceeds to kill the gathered UNION executives though Agent Simon manages to escape. Agent Simon is brought onto the Wheel of Fortune and sends drones to track and record Shub Abyss to help revert Shub back to normal.

Jaeri Kim analyses footage from the drones and studies Shub Abyss's behavior patterns before using a fluroscopy camera to discover that Shub Abyss has two brains. He finds that the brain in Shub's lower body, now the snake, is the main controller of Shub Abyss and suggests destroying it though its destruction might affect Shub. Agent Celine read Shub's mind and found that Shub was living in a constant nightmare but possessed a strong desire to live. Bai and Wolfgang carry out Jaeri's plan and succeeds in destroying Shub Abyss' lower brain, allowing Shub to regain control of her body. However, as Shub had killed multiple executives, she was sentenced to permanent quarantine at the Underground Prison that once held Veronica. In addition, Shub's lower body, still a snake, was arranged to be amputated as it continued to attract dimensional monsters towards Shub.

As Shub is escorted towards the prison, she meets Bai and Wolfgang and is seemingly depressed but accepts that such a fate was a fitting punishment. She also hints at a possibility that she can regenerate as she mentions that she would regain control of her legs after the amputation. However, as Bai and Wolfgang return to the Wheel of Fortune, the medical staff in charge of Shub's amputation sends an SOS. Bai and Wolfgang return to the Special Quarantine Area where they find Shub and the now dead medical team. Shub claims that Dust had arrived and killed the medical staff and pleads Bai to protect her. However, Bai had fought Dust before, and pointed out that the bite marks on the medical staff would not have been inflicted by Dust. Furthermore, Wolfgang's book was reacting to the evil that Shub now possessed. Shub reveals her frustrations at having to be imprisoned permanently and subjected to amputation. As a result, she was tempted by Dust's offer of turning back to normal and being accepted back into the Nameless Legion if she killed the medical team. Shub retreats, promising to return to kill Wolfgang with Wolfgang doing the same. Shub's newfound power continued to grow, resulting in the UNION's decision to activate the prison's device to weaken her. Alice, still traumatized by Shub's sudden change, reluctantly gives the order to Bai to eliminate Shub. Bai returns to the prison and converses with Shub, with the two coming to an agreement that they were both left with no other choice but to fight. After her defeat, Shub apologizes for what she has done and thanks Bai for reuniting her with her lover, telling her that she hoped Bai could now take a vacation as she fades away.

After her death, her evil is sealed within Wolfgang's book. Her thoughts, pain and remorse were transmitted to Celine who tells Wolfgang and Bai that Shub is grateful to them. Wolfgang puts up a strong front and calls Shub an idiot for being grateful to her killers, but Bai's grief is so strong that Celine senses it although she is usually unable to sense human feelings with her power.