He'll grow out of it. Heck, I wanted to be Indiana Jones AND Jackie Chan when I grew up. I'm never going to give up hope.
I wonder what it is about Five Nights at Freddy's that attracts the younger end of the spectrum. I mean, I can't imagine that most of them have ever played the games themselves, unless they stole Mommy's credit card and had a computer of their own to play it on. You'd think any parent worth their salt would see 'Jump Scare Animatronics and Child Murder: The Game' and think twice about letting their eight, nine, or ten-year-old buy it online. (Do they even sell most games in retail stores anymore?) Then again, in my torturous months as a GameStop employee, I did see quite a few elementary schoolers get GTA for Christmas.