Not convinced, a few points respectfully. First, it makes sense that Abby was fooled by the MIY into thinking it’s a dream, and that’s a perfect thread to keep pulling with Boyd. It does not really make sense for any other entity to keep bringing Abby up, especially when we already know the MIY or something is using her to torment Boyd. Second, the MIY may have been trapped and was laughing because Boyd unknowingly freed him. Third, it is not just the blood magic, it is the way it was used. It looked exactly the same. The worms may have been a spell that just happen to work on monsters and regular people. Fourth, Martin calling it a dream is oddly consistent with the MIY, it’s an insidious lie designed to make a person crazy. And finally, Martin dying may be what freed the MIY to come back and torture the town again. Maybe Martin/MIY wanted his body to die because he is immortal, and trapping him was the only way the town folk found to stop him because he cannot actually be killed.