History
When they were younger, they were split between their parents. Charon was taken by their mother and Hades went with their father. When Charon was about six year old, his mother died tragically- she was murdered. He saw it all while hiding in a closet.
He then was moved in with his Father and brother. Least to say neither boy couldn't quite understand what to do with the other. Both soon to learn to depend on each other though, since their father was hardly ever home. Four years after Charon had started to live with them, their father fell for a woman who had children of her own.
Since he wanted to please them more, the twins were basically pushed out of the household and onto the streets.
Ironically enough, this suited them fine for a while until Charon became quite ill and had to stay at the hospital when they were about fifteen. At this point they have been living out of a basement of an abandoned building doing what they could to get by.
They hadn't attended school since they were 'kicked out' of their own home so they had to educate themselves and find odd jobs they could get away with.
With Charon in the hospital, people were getting quite anxious about where they were from. It was Hades who applied to try out a new experimental drug that's suppose to help cure illnesses.
Unknown to Charon, Hades had come down with the same illness, but because of their finances and the fact that Charon was -physically speaking and in health wise- weaker of the two, he made the choice to enter them both as test subjects.
This would change their lives from that point on. They gained powers, they didn't know what to do with. Things were starting to become even weirder as they grew older and under the wing of Saphir who had given them the drug.
They soon learned their real calling and had a place to live and train.
Charon became careless with himself after discovering he could heal himself- but only himself.
Hades became enamored with Saphir's way of thinking and wishes to become closer to him. He came to understand how to manipulate shadows to hide himself and to turn off any light without much effort.
They accepted their lives now because they had nothing else to lose. Saphir had cured them of their illnesses.
It's only fair that they help him with his goals.