Commander of the starship which brought Mar-Vell to earth. He held a hatred for Mar-Vell for being an outstanding Kree warrior, and for the relationship that Mar-Vell shared with Una the Medic.
Major Story Arcs
After a successful mission to investigate the disappearance of Kree General Devros, Yon-Rogg is assigned command of the ship Helion, with Mar-Vell and Una the Medic as part of his crew. Their mission was to infiltrate and study the human race and determine their threat level to the Kree Empire. Sending Mar-Vell down to the surface, Yon-Rogg's jealousy of Mar-Vell's relationship with Una leads him to interfere and attempt to sabotage his progress repeatedly. First he paralyzes Mar-Vell and attaches a wrist monitor to him. Then as Mar-Vell is trying to return to the ship to recharge his breathing potion, Yon-Rogg fires a laser at him and imprisons Una for calling him out on it. When Mar-Vell escapes this threat on his life, Yon-Rogg reactivates the dormant Kree Sentry #459 and sends it to attack him. Mar-Vell defeats the robot, and when Zarek and Ronan the Accuser find out about the incident they reprimand Yon-Rogg for endangering the mission and order him not to do so again. He next refuses to help Mar-Vell as he battles the Super-Skrull, and then tries to prevent him returning to battle after he is first defeated. Further antagonizing Yon-Rogg, Mar-Vell thwarts his plan to divert a human rocket carrying deadly bacteria onto a city, leading Yon-Rogg to have Mar-Vell put on trial for being Un-Kree. After some further struggles between them, Yon-Rogg tries to break up Una and Mar-Vell's relationship by showing her video footage of Carol Danvers passionately kissing Mar-Vell after he rescued her from Cyberex.
The beginning of the end for Yon-Rogg was a mission to get Mar-Vell to ally with a shadowy group called The Organization. When the mission ends badly, with Mar-Vell killing the whole group and destroying their headquarters, Marv is sentenced to death by firing squad. An Aakon attack disrupts the death sentence, and leads to the death of Una. Mar-Vell battles Yon-Rogg, but ends up sent flying through space in a rocket, unable to return for the next two months. Mar-Vell finally returns, to which Rogg responds by sending the Man-Slayer robot after Carol Danvers. Mar-Vell saves her, but is then arrested for treason. Escaping, Mar-Vell is manipulated by Zarek and Ronan via a strange entity they created called Zo into a plot to overthrow the Supreme Intelligence. Mar-Vell thwarts the scheme and is rewarded with a pardon. On his way back to Earth, however, Mar-Vell is trapped in the Negative Zone. On Earth, Rick Jones, a longtime ally of the Avengers, discovers the Nega Bands in a hidden Kree station, and is telepathically convinced to allow Mar-Vell to share existence. When Yon-Rogg shows up looking for the Nega Bands himself, Mar-Vell switches places with Rick and battles Rogg. Yon-Rogg escapes by using a bomb disguised as Carol Danvers, and goes off to kidnap the real Carol, taking her to yet another Kree outpost on Earth. When Mar-Vell shows up, Rogg uses a machine called the Psyche-Magnitron to summon a Mandroid to attack Mar-Vell. Mar-Vell defeats the Mandroid by blasting the Psyche-Magnitron, causing it to overload. Knocking out Yon-Rogg, Mar-Vell rescues Carol and escapes before the Psyche-Magnitron explodes, apparently killing Yon-Rogg.
Revenge on Carol Danvers
Years later, Yon-Rogg resurfaces, seeking revenge on Carol Danvers, who has now become Captain Marvel herself. Yon-Rogg had somehow merged with the Psyche-Magnitron in the explosion and pulled himself back into existence by force of will. Rogg taps into Carol's memories via the piece of the Psyche-Magnitron in her head and sends constructs of enemies from her history to attack her, like dinosaurs, the Brood, Deathbird and the Grapplers. He kidnaps Carol's friend Rose and steals the final piece of the Psyche-Magnitron from Carol's apartment. Rogg then sends constructs of the Brood and an Acanti ship to attack Carol and the Avengers before trying to contact the Kree. The Kree reject his offer of Carol Danvers and the Earth, so he returns to Earth, intent on transforming it into a 'new Hala'. Rogg activates several hidden Kree sentries on Earth, needing 12 to complete his plans. The sentries combine with Rogg's constructs over New York, and when Carol attacks, she unwittingly completes the final part of the scheme. Despite the best efforts of the Avengers, Earth's heroes are unable to stop Rogg's plans. Carol, realizing she must sacrifice herself, flies high into Earth's atmosphere, giving herself a brain hemorrhage and cutting her link to the circuit. Yon-Rogg's plans are defeated and he is made powerless and is captured by Captain America.