[Well, this is an impressive display and Rossiu thinks he has some idea of what's going on here but--]

What's Halloween?

[...well.]

Is it some sort of festival that involves scaring people? There isn't anything like this back home.

[Judging from the background of the video, Rossiu's in a cave, so he's been missing out on the start of Halloween season. No one has explained this to him. Sorry, Jimmy.]