Magic Forums

Hi I'm not quite sure how to word this i'm semi new to this and I need to know how to summon a demon. I'm well aware of everything that can go wrong and am prepared for most outcomes i'm just having trouble figuring out how to summon one. (also a quick question if someone is possessed by something how can you tell without being able to talk to the person in real life? i've seen both their eyes go completely black before no white at all then they'd blink and their eyes would be normal and their personality has shifted completely sorry just a side thing)