He is still a Servant

"Hmmm?" Aether's gaze lingered blankly on the Empress's Maid, who stood before him dressed in attire typically reserved for boys.

The Empress's Maid, undeterred by Aether's scrutiny, simply patted down the folds of her clothing and met his gaze with a practised professional smile.

"So... you're not exactly a cosplay enthusiast?" Aether ventured, breaking the silence with a hint of curiosity.

A soft sigh escaped the Empress's Maid's lips, a sign of her patience wearing thin, "Took you long enough to figure it out... No, I'm not some eccentric cosplayer. I'm merely in disguise," she explained.

"Disguise? For what purpose?"

"... In order to safeguard the princess," she replied matter-of-factly... while lying through her lips.

"I see..." Aether nodded, piecing together the puzzle.

Pretty much she was protecting Aqualina in the shadows while making others believe she was Selene's Attendant.