Xavier was born and raised in England. He had a pretty happy childhood, and when he had developed his quirk, he started training with it with the help of his parents, since one had a time rewind quirk, and one had a future quirk.

He had a very happy childhood and very loving parents. His dad always played ball with him, his mom always read bedtime stories. The two watched movies with him, they hiked together, they played together. He loved being with them so much.

When Xavier was eight years old, his whole life changed. It was turned upside down. It became dark and twisted. He had a toy gun that he always liked to play with. So, he was playing with his toy gun, and he was aiming at a target. His mom walked by right as he fired his toy gun— only a shot went off. His mother was shot right in the head, and he immediately dropped the gun in horror before he ran to his mother's side, screaming for his dad.

His dad came and they rushed her to the hospital since she was still alive, though barely. Unfortunately, she didn't make it.

They went through a big ordeal on how it all happened, then the father and son were sent home. His father remained bitter toward him, all the way up until he was a teenager. It made it difficult for Xavier to handle. He never talked about what happened to his mom. Whenever she was brought up, he fell silent.

When he was sixteen, his uncle found a place for him in Japan so he could attend a school for heroes. Xavier packed his belongings before leaving home, not even receiving a goodbye from his dad. His dad didn't even acknowledge him.

Xavier got moved in with his uncle so he could attend school. Because of all the hero work he did, his age kept getting rewound. He outlived his father, who had never forgiven him, and he outlived his uncle. Because of his strange quirk and strange condition he may look young, but he has the eyes of an old man.

Xavier attends school all the time just because of his legal age. He hopes that one day, he'll reach eighteen, and he hopes that one day, he won't rewind his age to the age of a toddler or an infant and have to keep being placed with foster families, adoptive families, and go through school on repeat.

He is currently in Class 2-A of UA High at seventeen years old. At least, he is seventeen for now. Despite all of his hardships and reliving his school years, he does enjoy school, since it means he gets to meet all kinds of new people.