Matthew will be investigating and he will be a normal investigator, not a ghost. However, since Matthew did take Spirit Summoning and his plot skill from Bando, he is able to see and talk to ghosts. He hates it, but he can do it, and he would grudgingly agree to act as a go between when needed. So, I am definitely up for plotting stuff with any Investighosts or Infilghosts!

Also, at some point, Matthew needs to get possessed. Because obviously nothing can go wrong with the guy who's already sharing his body with a bunch of telephone spirits getting possessed, right? Right.