The Guardians of the Galaxy have a number of connections with different corners of the cosmic side of Marvel. But while some members of the team has ties to characters like Thanos, only one of them is the direct son of a universal ruler: Star-Lord, who in this world is the illegitimate son of the Spartax Emperor, J'Son.
Unlike Chris Pratt's Star-Lord in the Marvel Cinematic Universe, Peter Quill's dad isn't one of the all-powerful Celestials in the comic book Marvel Universe. However, he's still tried to recruit Star-Lord to his cause and has caused more than a little bit of trouble for Marvel's cosmic heroes.
KING OF SPARTAXX
As the only heir to Emperor Eson of the Spartax Empire, J'Son was a gifted pilot and soldier. He took part in a conflict between the Spartori and the Badoon, and was forced to make an emergency crash landing on Earth after his ship was damaged. He was taken in by Meredith Quill, and the pair grew to have a romantic relationship. J'Son eventually returned back to space to resume his war against the Badoon. In the name of protecting her from being targeted due to their connection, he erased her memories of him and departed back to the cosmos. He wasn't aware that she was actually pregnant with their son, or that this boy would eventually grow up to be Peter Quill, aka Star-Lord, asking discovering his intergalactic heritage.
Eventually, J'Son inherited the throne from his father and became Emperor. J'Son became an increasingly dour lord. He even had another child. After learning about the birth of his daughter Victoria, she was brought to Star Harbor, one of the premier military academies, and eventually became the Captain of J'Son's royal guard. But he wasn't made aware of his son into he was well into his adulthood, by which point Peter had become an adult.
FATHER & SON
Neither J'Son nor Star-Lord were particularly fond of each other. J'Son was disappointed in his son's roughness, while Peter was furious with how his father had abandoned him and his mother. The two came into outright conflict when J'Son joined the Galactic Council and moved for Earth to be made off-limits with intergalactic interaction. When the Badoon ignored this edict, Peter and the Guardians of the Galaxy went back to the planet and helped protect it, and J'Son ordered his Spartoi soldiers to take the team into custody.
He offered Peter the chance to come back to Spartax and rule by his side, but Peter refused. Meanwhile, the rest of the Guardians of the Galaxy were able to escape the traps they'd been left in by J'Son. Eventually, their human ally Captain Marvel arrived and helped free Peter. He exposed his father's crimes to the empire as a whole, causing the people to rise up in defiance and lead a coup against him. J'Son was forced to flee his empire and was dethroned.
MISTER KNIFE and THE UNIVERSAL TRUTH
Since he was dethroned, J'Son has become a consistent enemy of the Guardians of the Galaxy and Peter in particular. J'Son made a new life for himself as the intergalactic villain Mister Knife. He put together the Slaughter Squad. Their primary mission was to try and capture the Black Vortex, a cosmic tool that can unlock someone's celestial potential. Peter came up against J'Son while trying to rob him, and learned his identity. They ended up stealing the Black Vortex from him, leading J'Son and the Slaughter Lords.
J'Son also tried working with Thanos' son Thane to steal the Vortex back from them, but he ended up encased in amber. Although he was briefly held in the custody of the Collector, but Victoria arrived and rescued him to return to Spartax. J'Son was eventually freed from the amber prison he'd been left in. He even ended up as a member of the mind-wiping Universal Church of Truth. Indoctrinated in their ways, he's become the Patriarch of their faith. But even with his new awareness of the galaxy, he's still coming up against his son and his friends - while still trying to convince him to fight alongside him.