As an objective fact, Morgan, Gawain, Lancelot, and Tristan were undoubtedly the enemies of Reiger and Altoria.
Even if Altoria hadn't embarked on the path of a savior, hadn't tried to save the Fairy Country or rescue Britain, she would still inevitably be seen as a rival, as an enemy by those sent by the queen.
The same was true for Reiger, who had already developed connections with Morgan and others, experiencing several conflicts and major wars; they were essentially at odds with each other.
Yet, in such circumstances, Reiger felt that these enemies were much better than other fairies.
Although Morgan was a terrifying dictator, cold and cruel, viewing the lives of fairies in Fairy Country as disposable, for some reason, she valued Reiger highly and even conferred special protection on him, planting a "stake" in him.