Sly worked as a scientist in a remote private dimension called Paradisium. It functioned as a natural sanctuary funded by private benefactors for research and protecting endangered species of fauna and flora that came from different dimensions. Sly was quite happy working his dream job as a geneticist, studying the effects of dimensions and how they changed the biology of people and animals.

Eve, the head of Paradisium, was the most passionate of them all, encouraging creativity and drive. Sly had no complaint, until he started working with Verne, one of Eve’s long-time friends. The nervous man put doubts into Sly’s mind about Eve’s character and how her motivating passion was instead a dark obsession. Sly was brought into the involvement of Eve’s ‘commissions.’ To fund her own projects, she often worked with certain rich benefactors who would pay hefty amounts of money to create flawless test tube babies to be their future children. This discovery left Sly uncomfortable, though he kept working there, convinced the benefits outweighed the cons. Then he learned about the creation of X and Y.

He was taken in along with some others to study two teenagers who barely looked human due to their ‘beauty.’ They were X and Y, Eve’s passion project. Because of his friendly disposition, the two beings took a liking to him the most during their sessions. Because of this, Sly was promoted to become one of their handlers and monitor them more closely. He felt bad that they were cooped up in Paradisum all the time and tried to introduce them to the outside world so they could experience some humanity, though they had to be secretive about it. The three became unlikely friends and formed a bond together over time. He helped them pick their own names instead of the weird titles Eve called them, and they became Ezra and Yuuko.

Eventually, he couldn’t stand working with Eve anymore. She was spiraling down a manic obsession for perfection, and trapping her creations Yuuko and Ezra in a place where they never could truly live as people but be practically worshipped over instead. Sly tried to help them escape, with the help of Verne who also felt guilty about being involved with Eve’s work. Sly And Verne chose to steal incriminating information and research from Paradisium in the hopes to expose Eve’s corruption and shut her down. Sly, Ezra, and Yuuko escaped but didn’t get far. In the face of Eve’s wrath, Sly managed to slip away, but during the chaos ended up on an airship hauling away criminals. By mistake, he was cast down into a special dimension called The Underworld, where the worst criminals were sent to live and fend for themselves. Discouraged, but not deterred, Sly sought out a way to escape the ‘inescapable’ dimension to get back to his friends and rescue them. Sly ends up meeting Wings and becoming fast friends, and along the way, they pick up other strays, Kilit and Second, then Riven and Elaine who let them onto her Cargo Airship

Sly is a special case where he has two abilities. One is his natural dimensional ability, that everyone in his home dimension has. He can manipulate certain kinds of cloth and raw clothing materials to make them move. (think like telepathy but with clothes, he can make himself float)

His second ability was artificially given.

While he still worked at Paradisium there was accident and Sly almost died, but Verne helped save Sly’s life with Yuuko’s help. Verne’s dimensional ability gives him the means to reverse time on an object. (If a vase is broken he can reverse it to a time when it was whole.) He used this dimensional ability along with Yuuko’s regenerative blood transfusion to give Sly’s body the means for a quick recovery. This life saving treatment ended up with a jarring side effect, of not allowing Sly to die from injuries. Verne sealed Sly’s body to a specific state in time, where if he gets injured too badly the seal will kick in and reverse the effects back to when he was healthy. It doesn’t affect aging but it keeps him from dying via accidents etc. (One day I’ll find a way to explain this without it sounding so convoluted LOL)

When he experiences something that should normally kill him, he passes out for a few minutes and his body regenerates and reverses any damage done, and soon he’s back on his feet. Sly isn’t aware of this until he’s executed by some criminals in The Underworld, and finds himself still alive in a situation where he surely should have died. This TRAUMATIZES him but also makes him become very careless about his own life to a fault. (He need some MILK)