Gate on route 13 says people have spotted a mysterious Pokemon in nearby..

I know, but the Pokemon they are talking about is Kyurem.

why would they be talking about kyurem if you are the one to discover and catch it??

But kyureum is in challengers cave

I have all Unova Legendaries and after 500 hours of total play time I finally noticed that message in the gate of route 13. I only noticed the message because I went in the gate to look at the board to see if there would be something explaining why it had been raining on that route for so long. Sure enough, that message seems to have a link to the rain because the message went away when the rain finally stopped. Before the rain stopped, I was in the tall grass everywhere on route 13 hoping to find the mysterious pokemon, thinking that route 13 is the forest mentioned in the message. Unfortunately, I grew impatient and even went looking around and in Giant Chasm. I still found nothing. That was the day before the rain stopped. Now I'm here, just like so many other people who have seen the message, wondering what that mysterious pokemon was. I'm wondering if I missed a chance to catch something pretty darn rare.