User blog comment:BoltBlizard/Fortress Arrivers (TEASERS)/@comment-26434802-20150519171529/@comment-26434802-20150519175139

The weapon on the bottom left looks a little like a flare gun, so there's that.

The weapon in the middle could be a number of things. My first thought was a bomb, but after looking at it a little closer, and taking the other weapon into account, I think it might be a flamethrower.

Honestly no clue what that last one is. Maybe some dumbells or something.

So, judging by the evidence given, and the devil text, I conclude that the weapons belong to either Freddy, King Freddy, Chica (Because of the bomb) or the TF2 Pyro, which would make the "Guest from the earth" thing easier to understand.