Roeg is an older, middle-aged man. His dark hair is cut short, and he has a receding hairline. He is seen wearing glasses, a dress shirt and dark pants, as well as possessing the standard Military Police jacket, although he does not wear it in casual settings. He wears a bolo tie similar to that of his fellow military commanders.
Roeg is a very rude man, casually speaking of and criticizing others behind their backs. He seems to place a value in public appearance, showing great contempt for Historia Reiss's decision to mother a child with a simple farmer, and not having a public wedding; furthermore, he criticizes and mocks her on the fact that she was a nobody before she took power.
As noted by Nile and seen by several others, Roeg is quite a heavy drinker. During a meeting over dinner, he is seen emptying one bottle of wine and immediately ordering another by the servant waiting on them.
Roeg attends a meeting with other officers in the Military Police, ridiculing Nile Dok's misgivings at Paradis's decision to arrest the Anti-Marleyan Volunteers. Roeg defends the decision, arguing that they cannot afford to let the volunteers roam free when they know nothing of Zeke Yeager's true intentions, before lamenting that they were not able to have Historia eat Zeke immediately due to her pregnancy. Nile argues that Historia has the right to choose when and by who she becomes pregnant, but Roeg posits that someone from the volunteers, likely Yelena, gave Historia the idea to get pregnant immediately so that she will not be forced to turn into a Titan until after she delivers. As he concludes his tirade, Roeg orders a Marleyan serving them to bring him more wine.
After a bomb is set off inside Darius Zackly's office, killing him and three other military officials, Roeg and Nile present a report of the incident to the rest of the military's available officials. Before a conclusion can be reached about what to do with the possible culprits, the meeting is interrupted by the news that Eren Yeager has escaped his jail cell.
Roeg attends a meeting to determine a response towards the emergence of the Yeagerists. He questions how the group was able to assemble so quickly, and blames Hange Zoë for many Survey Corps recruits joining their ranks. Roeg then goes on to argue over the possibility that there are traitors among them. He is silenced, however, by the entrance of Dot Pixis, who berates the group for infighting in front of Hizuru's ambassador, Kiyomi Azumabito. After this, he silently follows the meeting until its conclusion a short while later.
Later on, Roeg and several others from the Military Police experience a sudden shock when Zeke uses his scream in the Titan Forest. He is imprisoned within Shiganshina by the Yeagerists along with other military soldiers who had drunk the wine infused with Zeke's spinal fluid.