The core strikeforce of ETD-6, the one who gets things done, the blade that swings at every anomaly crime. "Can I really say that? Isn't that exaggerating a bit?" "It's cooler than 'Your friendly ETD-6 member' for sure." Most people's first impression of Chaos is "that weirdo with the mask." At first, they find Chaos unapproachable, but as long as they spend some time with him, they'd realize that he's joyful, cheerful, and easy-going. The moment you start talking to him, the conversation flows like a tide, until he catches himself talking too much, or the listener becomes impatient, or a new mission notification rings. In combat, however, he transforms into a battle junkie. His willpower is as strong as iron; he never runs out of stamina, and he refuses to let go of his targets. Sometimes, he's so eager to catch a criminal, that he ignores everything else, such as the Bureau's rules and regulations. If you ask him about the rules, he'll likely admit that he's never figured out the Bureau's red tape or hierarchies. In fact, sometimes, he even forgets he works for the Bureau. Fortunately, he works for one of the most flexible units in the organization. His teammates in Unit 6 don't mind his quirks. It helps that their all-capable captain can always handle the fallout, so Chaos's habit of ignoring processes has arguably improved the team's performance. The captain, who handles cleanups personally, has made no comment on the matter. Chaos's Esper ability is summoning a mass of smoke that can be shaped into solid forms. The amount of smoke isn't fixed, but it never drops below a certain level. Chaos believes the output of his smoke corresponds to the past crimes of those around him, as he'd always generated more smoke in places with a criminal history. Still, that's only his theory. The actual mechanism remains unknown. "Is that how my powers work?" "Hey, why would you think I know your powers better than you?"

Before working for the Bureau of Anomaly Control, Chaos was once the graveyard keeper for Ghroth Island. He was responsible for overseeing criminals, not knowing that he would be catching criminals in the future. Eventually, a major incident—the jailbreaking of a dangerous Esper criminal—would push him to join the Bureau. Though it was not his fault, Chaos blamed himself for not monitoring the inmates more effectively. To make up for his mistake, he swore that he'd put in Ghroth Islalnd every criminal who deserves to be there. Only after that, would he return to meet the warden. Since no one could hold back Chaos once he made up his mind, the warden, who didn't want to overstep and cause trouble to the BAC, entrusted him to the Bureau and transferred him to ETD to deal with anomaly crimes.

Before entering Ghroth Island, Chaos was an Anomaly Hunter on a small island, where he went by his old name, Conrak. Eventually, he would abandon the name he received from his parents like a sunken boat in the sea. Conrak once got into a shipwreck with another 11 crewmates. They found themselves in an ocean isolated from the world There was an archipelago in the ocean, which didn't even have internet access. Conrak and his crewmates settled on one of the islands but never stopped wanting to go back. Unfortunately, no islander was willing to leave their home to ferry them across unknown waters, and no outside vessels passed through the islands. The group decided to build a ship and sail home by themselves. They named the ship "the Boulder." Once they built the Boulder, the group began to save up supplies for their return trip. For two years, the group navigated the Boulder around the islands to transport goods for funds. Since the group members were also Anomaly Hunters, they often took commissions, solving many issues that plagued the islanders. Gradually the "Boulder Hunters" became known local heroes. In the end, because the group lived peacefully on the islands and was praised as heroes, some of them no longer wished to risk another adventure to return. Only five of them decided to go back. However, on its return journey, the Boulder went through a storm. Conrak fell into the sea, and his companions weren't able to find him. Luckily, Conrak fell into the sea near Ghroth Island and was saved by a staff member. Once he formally joined Ghroth Island, Conrak changed his name to Chaos.

Long before the Boulder went on its adventures, Conrak was an ordinary boy living in a small seaside town. The sea was calm, and he would often stand at the shore gazing at the water, with no way of seeing the storms that would occupy the second half of his life. When Conrak was 13, his parents put him on a boat to travel far. They said they were preparing Conrak for the life of a sailor. Conrak didn't know that his parents didn't love him, nor did he know that he was seen as a burden to their struggling family. He merely believed that he would become a sailor, make a great deal of money, then take his parents somewhere far away for a happier life. He even brought home a dog, feeding it out of his own pocket money, hoping that when he was away, the dog would look after his parents. Conrak opened the last bag of dog food and kissed the dog on the cheek, then waved at his family and boarded the ship, not knowing it would never return. In fact, the ship was a smuggler's ship, and its destination was an uninhabited island, though it never got there. Midway through the voyage, the ship sank in a storm. Conrak awakened his Esper Ability, and black smoke took shape in the form of a ship. He and the other survivors miraculously made it through, carried by their abilities—only to find themselves in an ocean isolated from the rest of the world.

"You will die with infamy." Chaos found himself on the receiving end of such foretelling. When they were still building the Boulder, a mysterious old person stopped him suddenly and left him with these words. Somehow, Chaos never forgot them. At times, he would tell himself that unfounded words aren't worth dwelling on, but whenever a mission goes wrong, the words would come back to haunt him. Every omen from that island has come true. Even in doubt of his own fate, he brought countless wrongdoers to justice. That doesn't mean he pursues justice to defy the omens. He's had a passion for fighting evil and upholding good since he was young. The fortelling simply stirred a hidden, rebellious streak in him, making him more driven, until he became the relentless force against evil he is today.

There was an Esper who went by the name of Icaria on the Boulder. She was short and had a pair of wings, which saved her when the smuggler's ship sank. She usually enjoys zipping around, often joking that she never grew taller because her feet never touched the ground. Conrak called her "Shorty." Icaria didn't have any parents. She just had an older brother, who liked to make a big deal about working hard to raise her. The brother, however, never cared about her. That's why Icaria decided to stay on the island, though she was capable of flying home herself. Icaria died when the crew fought an anomaly known as the Kraken. Her wings were not made from feathers, but from some material that melted in high heat. During the fight, she tried to make the anomaly focus on her, but her wings melted when she flew too high and fell right into the Kraken. After that, Conrak was frustrated about the limitations of his abilities. He tried to experiment with what kind of shapes his smoke could form. Just before a battle, a bird flew past him. He thought that if he could shape his smoke into a bird, he could take to the sky. This idea didn't come at a good time: he couldn't apply it to the battle at hand, but it was enough to make him regretful… If only he had thought of it sooner, he could have saved Icaria. Nonetheless, the idea wouldn't have helped even if he had it earlier. Chaos is still trying to create flying birds with his smoke. Even after years of practice, he is still only able to create a few small birds that could fly a few meters, unable to even carry the tiniest speck of dust.

"In the 600th year, rain fell for forty days and forty nights. Waters rose upon the face of the earth, swallowing every hill and filling every valley until all was made plain." … … He said his name was "Plain," but that didn't sound like a real name. He's a mysterious guy. It's like he knows everything, but I've never seen him in a fight. He likes to claim that he's omniscient and omnipotent, and although he's never been wrong… I just can't help but find him annoying. Our boat is built. Plain said we needed to give it a name and proposed to call it "the Boulder." Hello??? Wouldn't a boulder sink in the sea? What an unlucky name! The others, however, seemed to like the name, especially that crazy woman with the vines, who said she'll write a heroic epic from the adventures of the Boulder. Is she serious? Plain even gave her his approval, saying that we'll all become heroes. Where did thIs confidence come from? … We're actually getting more and more commissions and we're getting more famous. Everyone thinks we're heroes. Plain has yet to be wrong. I do respect that. By the way, the boat is operational, and we can now call him "Captain." I don't like to call him "Plain," so that's a win for me. Anyway, if he truly knew about everything, why would he ever be sent on that smuggler's ship in the first place? … There've been sightings of a monster that resembles an octopus. Many people got hurt. We need to take it down. The captain hesitated for a long time before deciding to accept the commission. I'm not sure what's on his mind. I just know that it has to be us. During our strategic meeting, the captain kept telling Shorty to not fly too high. It's not like she can fly that high, right? … It's over. We won. Shorty died. I can't believe the crazy woman with vines drank too much and didn't show up. This was such an important fight… Had she been there, Shorty might have survived. But thoughts like this won't help… … We have enough supplies to go back, but some don't want to leave. They want to be "heroes" here… I get it. We don't know what kind of dangers lies ahead on our way back… but still, I need to return. I must return. … … Now I realize, my parents knew it was a smuggler's ship. I don't have to go back now… Ghroth Island is not that bad anyway.