Origin

His parents met when they were in service for the United States Army. They quickly fell in love and wed.

Adeline gave birth to a son named Grant Wilson(Ravager I).

Slade volunteered for a medical experiment in resisting truth serums. The experiment gave Slade enhanced strength and heightened reflexes. Shortly after this, Adeline gave birth to a second son, Joseph.

Slade soon was discharged from the army. After this he became a hunter.

After this Slade secretly became a mercenary known as Deathstroke, the Terminator.

In one of his assignments, Slade murdered a Colonel from the country of Quarac. The president of Quarac sent a terrorist known as the Jackal to find Slade, and find out who hired him to kill the Colonel. The Jackal kidnapped Joseph Wilson.

After this Slade admitted to his wife that his secret identity was Deathstroke. After Slade refused to give the Jackal the information he requested, one of Jackal's men slit his throat. Joseph was now mute.

A furious Adeline confronted Slade with a gun. Slade lost his right eye due to the gunshot inflicted by his wife (the shot was meant to kill him).

Adeline and Slade divorced and Adeline raised her two sons by herself.

Like his father, Grant attended military school. However Joseph was a musician and also a talented artist

Teen Titans

During "The Judas Contract" story arc, Adeline and Joseph approached Nightwing, offering to help the captured Titans. Joseph took the name Jericho.

Nightwing and Jericho saved the other Titans and brought Deathstroke to justice.

Jericho proved to be a loyal friend and teammate for the titans.

Death of Jericho

When the souls of Azarath merged with Jericho, he gained new abilities including a healing factor that repaired his throat and enabled him to speak.

The possessed Jericho's mission was to find a group of metahuman hosts for the souls.

He took over the Wildebeest Society.

Using them he captured current and former Titans.

Nightwing and Troia (the only remaining Titans) along with new allies Arella, Phantasm, Pantha, Red Star and Deathstroke attacked the Wildebeest lair and battled with Jericho. During the soul transfer process, Jericho begged his father to kill him. In order to spare his son any more suffering and save the remaining Titans, Slade Wilson was forced to drive a sword through Jericho, apparently killing him.

Jericho Returns

After some years Deathstroke discovered that Jericho had actually survived and taken refuge inside his body.

Jericho (inside his father's body) confronted the new formed titans, in a mission to prevent kids from becoming heroes. During the battle, Jericho's spirit was absorbed by Raven. Jericho's spirit was transferred into a computer file by Cyborg during a battle with Brother Blood.

Bombshell (hired by Deathstroke) infiltrated the Teen Titans and retrieved the computer disk containing Jericho. However the disk was recovered by Raven. Raven successfully brought back Jericho with a resurrection ritual.

Jericho rejoined the team and met his sister, Rose, for the first time. During the battle with Titans East he took control over Match's body, he has a hard time trying to control Match and has been living at Star Labs due to the danger

Powers

Jericho can enter and take control of a person's body if he makes eye contact. He can control their speech if they are not awake and he talks as they do in their body, if they are. He has good hand-to-hand fighting although he prefers to solve problems without violence.

Other Media

Animated Jericho

Jericho made two appearances in the Teen Titans animated series (Calling all titans, Titans together)

In this series he isn't able to talk, however when he "possesses" Cinderblock he is able to talk.

The fact that he is Deathstroke's (Slade in the show) son is never mentioned in any way.