Selion is an insufferable brat of no manners, so I can't imagine how he would be suitable to act as a princess's aide and bodyguard in any universe. Claire's own reputation would suffer if a brute like that was hanging around her all the time. After all, a person will be judged by the company they keep. Furthermore, an employer's fame depends on how the emplyees act. So, if Selion needlessly offended random people, like he tends to do, all of them would blame Claire for it because it would be her job to keep Selion in check. However, nobody can keep that rude boy in check. Selion is good for nothing but the battlefield.