something random

I am fighting the boss Justice Ironbriar the boss of The Cult Exposed and when I tap the blue sword to fight him I get the pictures of the other characters at that location and begin the fight with a random monster which I do and beat the random monster then I am taken back to Justice Ironbriar and the blue sword it their again and their is no other options I can see so I tap it and it brings back the portraits to select a character to fight a random monster I see no way to progress.