I'm guessing this is all a prank. Seriously. I have never seen anyone hack at all. He just must be some crazy scripter or something. I think it is possible to make yourself same power as host, and get the trust invite, and I think you can also set the player health too. Based on the information, it said that the invincibility only activated when he sat, and I can see why if he used some private script or something. Did anyone get his BL_ID?