"Demons are generally an unpleasant lot, mostly concerned with their own satisfaction or amusement, which very often ties into spreading whatever their associate madness is or, failing that, simply causing distress and gathering power. As far as power in between demons go, souls are what they can use the best, and mortal servants are the next best thing. So if a demon can, it will steal your soul. If it can't do that, it will try to possess you and force you to do its bidding. If it can't do that either, it will try to manipulate and trick you into doing what it wants. As I'm sure you're smart enough to realize, this means that when dealing with demons it is paramount to be aware of what is going on, to be as forewarned as possible, and to focus on what you are doing. The fastest road to accidents in demonology is, therefore, to summon when you are tired, drunk, distracted or otherwise not at full mental and sensory capacity. The second fastest one is overestimating yourself or underestimating the demon at hand." he paused for a few moments. "Usually, when starting out, novice demonologists work with demons that are weak enough for direct soul theft and possession to not be an issue, leaving only manipulation to watch out for at the start."