A.N. I made this theory on my own
So another theory for whoTrixis that he is Marella's dad who is also a Guster. (I think)When they were in Nightfall Vespera commented on how Marella was there despite how much her mom had worked to keep her away. So I think Caprise figured out Trix was part of the the Neverseen and then Trix pushed her of the balcony to keep her quiet.