How long did it take...

god told me through meditation.

I don't remember. I think they dropped a hint before you went in the castle. But if I went in and realised that all of a sudden my characters were doing so little damage I would think something was wrong. Then I'd probably go back outside and come back in again. Then when I went outside I might realise the castle was upside down, then maybe I'd pick up the hint that you are to junction your primitived weapons