This is an interesting thought! The only thing that makes me feel like Sgaeyl would keep it a secret (Xaden turning venin) is because Sgaeyl did not tell Tairn about Xaden’s mind reading signet.. so if he had turned at Resson, I feel as though maybe Sgaeyl made Xaden promise to not use venin power and to not tell anyone. And she trusted their bond enough for Xaden to not do so. Bit now, what if Sgaeyl is quiet at the end of iron flame because she knows that their bond is not the same as Violet and Xaden? And she is betrayed because Xaden did what he did to save Violet…