Elyra wanted to help Seth in this difficult mission and that's why she immediately agreed with what that mysterious lady clad in a white rob had told her. Actually, Elyra and the Elf Queen, just like Lilian, received a mysterious guest some days ago. That guest had told them about the things pertaining Seth's situation and because of that, they were able to arrive there in time.
At the current moment, Elyra thought that if she were to finish this battle earlier, she might have the chance to help him a little bit more. That's why she decided on the second option and instead of playing this game of patience, she chose to cut Second Shadow's routes and slay him with her sword.
