Jason's destiny was written before his birth.  On the surface, his birth parents seemed to be a normal middle-class couple, but his father maintained a secret double life, unknown even to his wife.  Secretly he was a member of a dark, devil-worshiping cult and, in exchange for promises of great wealth and power, he'd promised his first born would be host to a demon under the cult's control.  It was not until some time after his birth that his mother found out about his father's dark pact.  At first, she could not believe that it was true, but the increasingly disturbing behavior of her baby, along with the dark dreams sent to her by the lurking demon in human form, convinced her of the truth of the matter.  Knowing that she could not allow her own child to live a life of torment and servitude, she did the only thing she could think of.  Keeping her knowledge a secret from her husband, she plotted to kill both him and the baby, hoping death would free her child's soul.

Authorities drug the car out of the river later that same day.  Both the father and the mother were dead, but the child, Jason, had somehow miraculously survived (though Jason would later find out that it was actually the demon's protection that saved him).  Jason was placed into foster care, where he was moved from family to family.  Greatly trouble, even for a foster child, Jason's foster parents rarely could control him for long.  He was prone to fits of rage and was constantly plagued by nightmares due to the demon's influence.  However, the demon was never able to take full control of the boy.  This was because the spirit of Jason's dead mother was doing her best to protect her son and hold the demon back.  For many years this cycle continued, his mother's spirit becoming weaker and weaker over time.

Finally, one night, Jason's mother appeared before her teen aged son.  This time, however, she did not come to him in a dream but rather appeared as an apparition while he was conscious.  She told him that she could no longer hold back the demon's full influence.  If he did not want it to claim him fully, he would have to fight it himself with the force of his will and faith.

When the demon came to him later that night, Jason fought back with everything he could.  His form began to change.  Bat-like wings sprouted from his back, his muscle and bones twisted into a hulking mass of blood-colored scales, horns and talons.  However, while the demon was able to change his physical form, Jason was able to retain his mind as he fought the demon back.  When he forced the change to reverse itself, his mother appeared to him a final time, letting him know how proud she was.  She told him of the pact his father had made, though she did not know the full details of what cult his father was part of, why they wanted control of the demon or even which demon it was he had been promised to.

Since that day, Jason has sought answers about his father and the cult that did this to him.  He has spent many years pursuing leads, and has become quited adept at tracking people down.  He puts these skills to use to earn money by taking up government bounties.  He prefers to chase down criminals known to have occult ties, in the hopes of finding more information about what cult his father belonged to.  Not only could he get his revenge, but they were his only lead on how to exorcize the demon, as no other method he has tried has worked.

About a year ago, while hunting down an escaped cult leader, Jason met Detective Adsila Lowrey.  She was investigating the same cult that was harboring the convict.  Leery of each other at first, the learned that they had a common enemy and similar purpose.  Together the destroyed the cult, bringing both the escaped convict and the leaders of this cult to the police.  Since then, he has hired on as a part-time consultant when Detective Lowrey needs extra muscle.  In return, she promises that should he ever loose control of the demon, she will make sure it brings harm to no one, even if she has to kill him to do it.  She has also devoted significant time and resources into helping Jason track down the cult responsible for his possession.

Jason tends toward moody stoicism as he must always keep his emotions in check, lest the demon try to exert its influence.  Any strong emotion, but especially those tied to the Seven Deadly Sins, can be used by the demon in its attempts to take control.  As a result, Jason rarely shows any emotion and keeps most people at a distance.  This and his career of tracking down scum has given him a very dark and cynical view of life and humanity.

Jason's powers come primarily from the demon residing within him.  However, he's reluctant to use those powers as the "voice" of the demon becomes "louder" when he changes forms.  As a result, he cannot stay in his demonic form for long before the demon starts to assert its own personality.  Still, even when he's unchanged, the demon is constantly "whispering" in the back of his mind, encouraging him to follow his baser instincts.

While in his demonic form, Jason is both very strong and resilient.  However, he's also rather slow and "clumsy" for an average PC.  Also, while highly resistant to pain and damage, Jason is far from invulnerable.  He rarely ignores all damage from an attack, and can certainly be whittled down in a protracted fight.  As a result, it sometimes takes him a long time to recover between battles.

Aside from his powers, Jason is a competent man-hunter and knowledgeable about the law (at least as far as it pertains to bounty hunting).  Also, he enjoys tinkering with cars during his spare time and can often be found either tinkering with his truck or doing routine maintenance on Detective Lowery's company van.