Dipper is going to start the plot out in "Let's solve the mystery" mode, trying to teamwork and do the supernatural hero thing, but eventually he's going to turn into a monster. When he starts succumbing to the monster call he's going to be really creepy and start acting like the setting and all the horror is normal. Then when he turns, he'll be a little horror monster, complete with eye horror, claws, teeth, and out of control poltergeist-style telekinesis.

I'm totally game for teamups at any point during all that!