OriginJericho was the son of the second Head Mistress of H.I.V.E.. Adeline Kane Wilson and Slade Wilson, for years Joeseph had no idea his father was a supervillain and mercenary. Jericho first discovered his powers when he locked eyes with an injured friend in his youth and found himself in his friend's body, he walked his friend to safty and to get medical attention, although the experience was very traumatizing for Joseph, repressing his powers and leaving him mute. Adeline eventually divorced Slade and established her own wet works team called Searchers Inc. Joseph worked closely with his mother and received military training from Searcher Inc and took up the codename "Jericho". One day when his mother was about to meet her end at the hands of an assassin, Jericho, who could not reach them in time, could do nothing but stare down the man from across the room, when he did his powers manifested and he was able to possess him, saving his mother, it was the first time since his child hood Joseph was able to use his powers. It is believed Joseph was born a mutant as a result of the gene therapy Slade had been through before Joseph was born. After discovering he was a mutant Jericho kept helping his mother as she was keeping track of Deathstroke. They eventually reached out to Deathstroke's arch-enemy Dick Grayson, AKA "Robin" AKA "Nightwing" and offered to help him stop Deathstroke.
CorruptionFor years Jericho was a member of the Titans and used his powers to stop many super villains and became a close friends with his fellow Titans and in a relationship with the Titan, Raven; Jericho's link to Raven would ultimately be what made him lose control. When Raven felt her father, the evil demon Trigon, trying to use her as a anchor to the world Jericho used his powers to enter her and help her confront him on a spiritual level in Azarath, Raven's homeworld. Trigon was eventually defeated, or atleast driven back, but Raven had now been brought to the attention of the souls of Azarath, who had been corrupted by Trigon and tried to possess her but she had well protected herself against possessions due to the threat of Trigon and so the soul of Azarath instead possessed Jericho.
The souls of Azarath were too weak at first to affect Jericho and so they remained dormant for a long time, eventually though they were able to overtake Jericho. They used Jericho to possess many of the Titans and each time Jericho possessed a Titan one of the souls of Azarath was left behind in one of them after Jericho left. Jericho also invaded the Wilderbeest Society a group of supervillains and used them as a large-scale group to place the rest of Azarath into. Nightwing and Deathstroke teamed up to stop Jericho and fought their way through the Wilderbeests to stop him and tried to reach out to him. Jericho became his old-self briefly and asked Deathstroke to kill him, Deathsroke obliged his son's request.
Years later Deathstroke found out Jericho has inadvertently possessed him but was lying dormant in Slade's body. When Deathstroke tried to have him exorcised it awakened Jericho and he used Deathstroke to confront the Titans. Jericho eventually revealed who he really was to the Titans and left Deathstroke body-hopping from one Titans to the next but Raven used her powers to absorb Jericho into her mind and keep him subdued. Sometime later when confronting Brother Blood the Titan, Cyborg downlaoded Jericho out of Raven's mind and on to a computer disk. Raven eventually was able to steal a resurrection ritual from Brother Blood and used it to not only bring back Jericho but restore his spirit to what it had originally been so long ago. Jericho was restored although his powers were somewhat warped at first from the process.
Jericho's soul was restored but his mind was another matter the years of possessing super villains had caught up with him upon his restoration and he left the Titans almost as soon as he was welcomed back to try to deal with his psychological issues. Jericho went mad despite his best efforts to compartmentalize and tried to assassinate a politician in a series of suicide bomb attemps. When the Titans found out Jericho was behind the bombing and was mentally unstable they tried to stop him but were unable. The hero Vigilante hunted down Jericho when the Titans failed, though he had been asked to spare Jericho's life. Viglante stopped Jericho by cutting out his eyes, the catalyst of his possession ability.
Once Jedricho eyes were gone and his power neutralized he had a long time to safely work through his issues. Jericho's eyes would eveutally be restored by the Black Lantern Corps but luckily by then Jericho had come to terms with his psychological issues and dedicated himself to helping make-up for his crimes to the Titans and the world.
Other MediaJericho appears in the cartoon Teen Titans. Although he is not seen as a villain in the show and only in his capacity as Teen Titan. Also the link between him and Slade is never made. Jericho appeared only in the last few episodes of the series and so many details about Jericho are never explored though his powers are quite clearly demonstrated as he uses them to help Beast Boy defeat the Brotherhood of Evil.