|“||You've still got attachments to humankind? Look! At the darkness! Look at this blackened world! Look at the end of humankind! All that's left is to clean up the trash! Burn to ashes each human worm stubbornly clinging to life, along with their towns! You received power in order to destroy the world!||”|
|— Kirio Karasuba, Rise|
Kirio Karasuba (烏葉力男 Karasuba Kirio) was the thug who was apprehended by Kyohei.
Kirio is rather arrogant, considering himself to be superior because he can control his transformation and mentality as a Goblin. He is brutal and revels in destruction, believing that it is their responsibility, as the self-proclaimed new "gods" of this world, to wipe out the human race, merely because he believes that they are weak creatures. He is also shown to be manipulative, attempting several times to convince Teppei to give in to his primal instincts and help him in his bid for world destruction. However, when someone goes against his ideology, he quickly flies into a rage, as seen when Teppei stated that he won't be like them and that he would protect others.
Kirio is a tall man with long, dark-colored shoulder-length hair, thick dark-colored eyebrows, and wrinkles around his eyes, nose, and mouth. He wears a light-colored, button-down, long-sleeved shirt with the sleeves wrapped up past his elbows, which sports a pocket on the left-hand side of his chest, light-colored pants, a black belt, and light-colored shoes.
When Kirio is partially transformed he keeps his clothes and most of his features. However, his nose grows longer and more bulbous, he gains sharpened teeth and pointed ears, and his hair grows and becomes wild.
In his fully transformed state he loses his clothes, and his hair grows considerably longer, but just as wild as his partially transformed state, with dark-colored hair covering his lower regent. He retains the bulbous nose of his partially transformed form, with more pronounced points to his ears, alongside the sharpened teeth. He also has two small horns growing out of his skull.
Kirio used to be a member of the Hizuka Group, an affiliate of the violent Kiyanagikai Syndicate. At some point, he committed fourteen counts of kidnapping and murder, earning him the ire of Kyohei Ushizume, who would later arrest him.
After a day, He finds Teppei and takes him to an apartment to explain what has happened. He then explains that was they are and that it is happening all over the world. He also explains that since they are the new gods of this world then they have a responsibility to wipe out the weak humans of this world. He then shown Teppei what has happened to him and that explains what will happen to Teppei. He also explains how he is able to transform and that he is able to keep his mentality. When Teppei recognizes him and says that he will report him, Kirio taken Teppei outside and brings him to the destroyed police station.
Later that night, Kirio finds Teppei again, who had run away earlier, and shows him how dark that town is and that its the end of the humankind. He then brings Teppei to the chalkboard to shown what the humans had written down, and then destroys it while saying that the humans are weak. Kirio then gets angry when Teppei says that he isn't going to become like then, and blast Teppei away. He then catches Teppei and slams him into the ground. He is then wounded by Teppei and gets more angry. He then tries to shred Teppei apart, but it does nothing to Teppei. Kirio is then defeated and killed when Teppei attacks.
- Transformation Control: Kirio is capable of controlling his transformation and keeping his mentality. He is also shown to be capable of partially transforming parts of his body into his fully Goblin form.
- Superhuman Strength: Kirio has shown to have amazing strength, as seen when he was able to jump far distances. He has also shown to be able to slam a fully transformed Teppei into the ground and leave a crater.
- Aerokinesis: Kirio was shown to be able to use the wind to levitate himself in midair. He has also been shown to be capable of using the wind to destroy a chalkboard that Teppei was looking at, and even used it to send a fully transformed Teppei flying.
- Teppei Ushizume: Kirio had sought out Teppei in order to teach him about what had happened to the world. While talking to Kirio he reveals that he wants to see Teppei become a wild beast and burn down the town. He even tries to break Teppei's will when Teppei mentions that his dad would stop him. After he fails to make Teppei into a wild beast, he tries to kill him.
- Kyohei Ushizume: Kirio was orginally arrested by Kyohei before the goblin outbreak. After the outbreak he thinks very little of Kyohei and laughs when Teppei says that his dad would arrest him.
- Kirio Karasuba Vs. Teppei Ushizume (Lose)
- (To Teppei Ushizume)"We are the transcenders of ancient times!! Devils!! Or maybe gods!! Those who have been chosen!! Those who have returned home!! It's not only this town, but the whole world that's become like this!! The Era of Chaos is here again!!
- (To Teppei Ushizume) "You've still got attachments to humankind? Look! At the darkness! Look at this blackened world! Look at the end of humankind! All that's left is to clean up the trash! Burn to ashes each human worm stubbornly clinging to life, along with their towns! You received power in order to destroy the world!"
- (To Teppei Ushizume about the blackboard) "A big old steaming pile of the losers' whining. Just looking at it makes you sick to your stomach, doesn't it?"