If I'm remembering correctly the man with his tongue cut out is the friend of the MC. At the end of the main story you get the scene where the friend runs after the hog, leaving the MC at the house and then the ML comes up and grabs the MC and they walk away to basically live life together. Since the friend remembers leaving him at the house he's probably terrified and confused on where his friend is. So he's looking around following these murders hoping that his friend isn't one of them. I MAY BE COMPLETELY WRONG!! Just a thought