I got this idea when I had the episode running in the background, listening only to the sound. In the scene where Kid's-Show-Host-Joey-Graceffa shows up in the house, he's covered in Kensington Gore and Slasher Smiling. His line is simply, 'Hi Karen.' In context, it's straight up Nightmare Fuel. But if you listen to only his voice, he doesn't sound malicious; he sounds like a sleepy child waking up to see their favorite person. In addition, the over the top personality, bright colors, and animal sidekick make him seem like some sort of cartoon character in human form. If a cartoon character were in a human's body, they would be ridiculously strong and practically invulnerable. It's possible that the murders were all cases of And Call Him George.