Unlike many of his people, Orion was born in Doskvol. His family claimed nobility status and lived comfortably for a time, but his father's desire to "live well" drove his family into debt, which resulted in the night several men came to Orion's home and helped themselves to his mother and twin sisters before removing them from this world.
Orion was at school at the time, and was released to return home as soon as he found out.
After the funeral, Orion confronted his father, who had taken to the drink. In a cold rage, Orion struck his father down, then set fire to their home and made his way into the underworld.
It was the last time that Orion would ever allow his temper to control him.
Shortly after taking his father's life, he felt a burning pain on his right breast. Ripping off his shirt, he saw that a sigil had been branded into his chest. When the pain subsided, he realized that there was someone else inside his head. It explained that it was bound to the head of his clan, who was not Orion. It introduced itself as Fal'Thng, god of gnashing teeth. It explained the pact that had been made: in exchange for allowing Orion to release it regularly, he would attack Orion's enemies and help him in his endeavors. Orion agreed, and the pact was renewed.
Realizing his money would be temporary at best, Orion decided to invest in a business: one that was in a position of both desperation and something that would allow him to support himself while he decided what to do from this point forward.
Enter Salia.
A skilled information broker, Salia was under siege by several competitors who were attempting to drive her out and take over her turf. Orion's rather large infusion of coin allowed her to drive out her immediate rivals, and in exchange, Orion gets a comfortable lifestyle.
Deciding he wanted to start making his way through the underworld, Orion joined several different crews, never staying overlong as he often encountered people he considers beneath him; actually, if pushed to answer, Orion would admit that he considers EVERYONE beneath him.
It was in one of these crews that Orion met the man who would become his main competitor, though he would never admit it.
Augus.
Augus had a position as an architect, which allowed him access to many of the buildings throughout the city, which even Orion had to admit made the jobs they did together quite easy. For his part, Orion had by this point gained a reputation for both his near obsessive planning and ability to adapt to situations on the fly. His detractors would often also point to his reputation as an "egomaniac" or "arrogant a@#hole".
Everything, however, is in service to his overarching goal: to gain control of the city's underworld.