He was referring to the crown prince since Carsillion was hiding his identity that time. (=・ω・=)
Carsilion is referred to as “Your/His Majesty”
yeah i’m aware of that but when they were looking for a solution one of them said us and his highness but then she pointed at carsilion and said that he contains much more power
Basically, Carsilion planned to disguise as a lowly mage (or a person who doesn’t have a power as he said to Aria) and see for himself if Aria is Charlotte. So the knights and mages from Claus thinks that he is a normal mage and not the emperor of Marveil.
wasn't carsillion "his highness" i'm confused i thught he was crowned as king