Stranger Things, if it's included, makes me think one of two things,
1: It will be a lighting effect, done at randomized periods almost as if it's a mini-show to where it will look like a normal set (perhaps the D&D table and basement in a contained aspect), and then transforming itself to look like it's from the Upside Down.
2: It's the Upside Down, and it's the Demogorgon.
If it's 2, god security is going to be there.
For TrT, the obvious comes to mind, Sam.