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 Mar-Vell and Carol Danvers appearing to hug and kiss after Carol was rescued by Mar-Vell.