I could be mistaken but Royst (the red headed disciple of Schanuzer) was introduced as a guy when he attacked the academy to meet Kayden's apprentice. Appearance wise, definitely looks more female than male
And Ashtauriel, I pretty much agree with your call. Royst (suspected something happened when the sharp decline in speed and given Duke's confidence (both before the fight and after Jiwoo was wrecked), probably suspected he was involved in said something. Despite those adverse conditions, Jiwoo managed to bring down her junior disciple