Basically a gate shuts and a lynel is let loose. It was the first lynel I fought in this game, but I made quick work of it as I had a 57 weapon and my three sages helped a bit as well. Anyway, then comes the next tier of lynel, and then the next. And then a goddamned silver lynel. At this point I'm running out of decent weapons and fairies. Furthermore I hadn't prepared more than one meal which could get rid of the gloom damage, of course I had consumed it at this point. So I'm fighting a silver lynel with 5 hearts and my only source of recovery is fairies. I actually manage to do it in my second try, but he wasn't the final enemy.
I ended giving up as I simply didn't have anything to deal with it. But now I know how to prepare for that shit.