Capítulo 824: Dangerous Failsafe.

Rita's transformation was preceded with her body burning up in purple flames after which her skin turned purple and she unleashed demonic wings as well as a tapered tail which she stabbed at the Empress with.

Harlyn looked surprised at the transformation as she avoided getting stabbed by the tail but she quickly noted that it was not totally unexpected. 

All veils had been cast away and the nefarious nature of the ladies of the Sapphirine Cult was not exactly going to be a fresh thought anymore. It should be expected.

Harlyn just continued the motion she had been making with her fists for yet another blow to Rita's face but the demonic woman was not having it. 

With her physical stats boosted by her demonic transformation, she was able to intercept the blow and stop it in place before making an arrow of lust flames and shooting it at the Empress.