J'son was the only son of the previous Emperor of Spartax, and therefore sole heir to the throne. He was summoned by his father when war broke out between the Spartax and the Badoon. On his way back home, he was forced to crash land on Earth, where he fell in love with a human woman named Meredith Quill. The two began a short relationship before J'son was forced to leave to wage war for the Spartax. Meredith would later go on to give birth to his son, Peter Quill.
Loss of his empire
Years later, J'son joined other members of the Galactic Council to declare the Earth off-limits to extraterrestrial interaction. Once his son defended Earth from a Badoon attack, J'son sent Spartax soldiers to capture him and his team of Guardians of the Galaxy. However, the Guardians managed to escape and flee.
In an attempt to finally get rid of the Guardians and make his son join him, all of the Guardians were separately dealt with by the Spartax Empire and its allies. However, they didn't count with the Guardians' ally Captain Marvel, who saved Peter Quill from J'son and the Spartax Empire. As he was escaping, Quill discredited J'son to the whole empire, revealing him as a heartless murderer. The entire Spartax Empire rebelled against J'son, who was forced to flee.
With no longer an empire or fortune, J'son became the villain known as Mister Knife, and started building a criminal empire. He put a bounty on his son, and also assembled the Slaughter Squad to recover the Black Vortex.
Because of the price put on his head, Star-Lord began raiding Mister Knife's crime syndicate, unaware that he was dealing with his own father. When the Slaughter Squad managed to finally capture Star-Lord while he was on a date with Kitty Pryde, Mister Knife revealed his identity to his son. After Peter escaped with the help of Pryde, who travelled all the way from Earth to save him, J'son tracked down to a planet the son of Thanos, Thane, and convinced him to join his cause.
Star-Lord and Kitty Pryde decided to steal the Black Vortex from J'son with the sole purpose to annoy him, in retaliation, Mister Knife sent the Slaughter Lords to hunt them down and recover the Vortex. After numerous failed attempts to recover the Vortex, Mister Knife managed to get his hands on it. As part of a deal with Thane, the son of Thanos submitted to the Black Vortex and used his cosmically enhanced power to encase the entirety of Spartax in his amber construct. The trapped Spartax was later traded to the Brood by Mister Knife, in exchange for taking advantage of their expansion and acquiring one planet for every ten worlds they conquered ever since.
At a moment when Captain Marvel retrieved the Black Vortex, she was cornered by Thane and J'son, who demanded she give them the Vortex back. When Thane tried to use his powers to encase Carol in amber, she used the Black Vortex as a shield and deflected the attack towards J'son.
J'son remained encased in the amber construct floating through Spartax's orbit after the planet was freed by Kitty Pryde, until he was found by the Collector, who was too late to recover the Vortex, but settled for adding J'son to his collection. While still encased in amber, J'son was recovered by his daughter Victoria and brought back to Spartax.
- During his time as Mister Knife, he used a flying fortress, a spacecraft made in the body of a giant alien creature. This spacecraft had enough firepower to destroy a planet, as seen when the planet Hala was destroyed by it.
- Although inspired by the Emperor Jason of Sparta who first appeared in Marvel Preview #11, the current Earth-616 incarnation of J'Son was created by Brian Michael Bendis and first appeared in Guardians of the Galaxy (Vol. 3) #0.1.
- Prince Jason of Spartax who first appeared in Inhumans Vol 3 2 was originally meant to be a younger version of this Emperor J'son and the future father of Peter Quill. That Jason was a member of the Spartoi race and heir to the throne of the Spartoi Empire that existed in the Greater Magellanic Cloud of Reality-616. However, a retcon in Guardians of the Galaxy (Vol. 3) #0.1 revealed that the father of the Star-Lord who was born on Earth-616 was actually a member of the Spartax race from another planet named Spartax and heir to the throne of the Spartax Empire that apparently existed in the Milky Way Galaxy. Subsequently, it was decided that classic Emperor Jason, his empire and the Star-Lord who was his son actually existed in the Earth-791 reality. This left Prince Jason from 2000 as character separate from both the classic Jason who appeared in 1977-1980 an the modern J'son who appeared from 2013 onwards.
- The idea that J'Son is a member of the Spartoi race is a holdover from when Prince Jason of Spartax, the heir to the throne of the Spartoi Empire, was presumed to be the father of this reality's Star-Lord. However, since the Bendis retcon, the name "Spartax" has been used exclusively in in-story references to J'Son's race. Specifically, he is a member of the Spartax race who ruled the Spartax Empire from their home planet of Spartax. Despite this, no official distinction between the Spartoi race who appeared or was mentioned in stories from 2000 to 2011 and the Spartax race who have appeared since 2013 has ever been made.
- 35 appearance(s) of J'son (Earth-616)
- 4 minor appearance(s) of J'son (Earth-616)
- 20 mentions of J'son (Earth-616)
- 13 image(s) of J'son (Earth-616)
- 3 quotation(s) by or about J'son (Earth-616)
- 2 item(s) used/owned by J'son (Earth-616)