So in the latest trailer "Lost in transmission" We can see some mysterious lovercraftian like creature when Mono jumps into TV. There's also one of the concept arts of the human which entire body is coming out of TV. We can see the lovercraftian creature on the cover of the artbook from collestor's edition (that I preordered btw)

So my theory is that-the true evil force in this universe is actually that mysterious lovercraftian being. It's like the entire separate dimension / world is evil entity itself and the TV's are the connection of the Little Nightmares world (the one that We play in) and that lovercraftian entity world. Maybe that evil living entity world is the nightmare itself or smt.

How's it releted to Broadcaster? I have 3 versions.

1. The Broadcaster is the man who discovered that evil entity and used it to corrupt the world. Why? Easy-He could be manipulated, or possesed by it. Or He could start to examine / study it and get absolutely crazy, I mean-My theory assumes that this entity is responsible for the corrupting singals, so The Broadcaster could get corrupted by it in the first place and that's why He started to send signals across the entire world. That entity wants to get free, wants to corrupt / destroy / turn world into it's nightmare version.
2. Second option is that the Broadcaster is the hallucination caused by signals. The signals send by entity creates that phantom (Broadcaster) who appears in every Human mind. The Broadcaster is like a guardian / warrior of the entity. Broadcaster don't exist in normal world, but it's the hallucination visible for everyone, like He exist in mind world, I don't really know how to explain this.
3. Third option it that The Broadcaster is the Entity itself. When entity got acces to Little Nightmares world it took form of the Broadcaster to interact in it, chase Mono and Six, fight etc. I think that The Broadcaster character don't really live in Little Nightmares world, but instead He's located in TV's-that's what I imagined all the time and now adding that to my theory it could be simply that the Entity is taking Broadcaster form when going into Little Nightmares world.

So yeah, that's my theory about true villain of this universe. Tell me what You think about it, if You want of course.