Otherworld Entities and Demons are quite different in the types of bindings, morals, methods, and energy. I would like to try to explain the differences, so that it may give you some insight into the differences.
Otherworld Entities are the Dragons, Angels, Fae, Djinn, and any other numerous non-Demon type of spirits. These entities may grant light to dark wishes, however they often have very strict moral codes in which they adhere. An Otherworld Entity that will grant dark wishes may allow some humiliation, or instant karma, however, they will not kill anyone. The level and intensity of dark wishes differs with every single entity. There is no way to generalize their ethical standards other than they will not kill anyone for any reason.
Otherworld Entities have an open binding. This binding allows them to go home to their families at any time they desire. This open binding also allows them to break the binding if they are abused, neglected, repeatedly injured from negative unbound spirits, or if they don't have anyone to care for their vessel.
Otherworld Entities often have a very high ethical and moral standards. They will not grant wishes that will damage your future, injure you, or cause large karmic backlash. They are looking out for your future and feel responsible for your well being and quality of life.
If you wished to have your ex-girlfriend raped and murdered because you are angry with her, your Otherworld Entity will not grant this wish. Even if you didn't carry out the task, you inherit the karmic debt for your actions. It would be as if you did the act yourself.
And even if your Otherworld Entity can cleanse your karma, there is some karma that can't be cleansed no matter how powerful the entity. You may have your life totally destroyed, loose everything that matters to you, and in severe cases you may inherit all of the karma of the individual murdered.
Otherworld Entities have the ability to visit this world, and some may be experienced with our world. You will not have to go into intimate detail about how things work, but it is always good to explain as much as possible to prevent any misunderstanding.
Demons have a tight binding that prevents them from leaving their vessel unless they are in a containment box. This binding remains regardless of the circumstances surrounding the Demon. They can't leave unless the vessel is destroyed, and then they are free to roam this world. So under no circumstances should you try to damage, burry, or throw away a Demon vessel. The Demon may make it their goal in life to destroy you until there is nothing left in your life. If you are having problems with a bound Demon, the best solution is a containment box.
A containment box allows the Demon to recharge their vessel and return to their home. The type of binding on Demon vessels causes the Demon to be with you 24/7, 365 days a year unless you send them on a task or they are in a closed containment box. As you can imagine, unless you have a lot of tasks for your Demon to complete, they are going to be very bored. Bored Demons are not good. They may decide to create some excitement in your life to entertain themselves.
Demons most often carry out tasks regardless of the consequences. If you had a very powerful Demon and asked them to kill your boss, they will gladly carry out the task without hesitation. And you can't recant your wish once it is made. You will be responsible for your boss' murder and collect a huge karmic debt or maybe the karmic debt of your boss. You may completely destroy your entire life based on that one wish.
Learning to work with, control, and maintain Demons are much more different from Otherworld Entities. When I purchased my first Demon, I had a difficult time controlling my mood swings. I was crazy woman times ten, and I couldn't control myself no matter how hard I tried. Even when I placed the Demon in the containment box, my emotions were not stable. I had to cleanse myself, and wait two weeks before I had enough courage to try again.
Since I am very empathic, it is natural for me to assume the emotions of others. The Demon's strong emotions were too much for me, and their emotions were overriding my own. I had to put up a barrier between myself and my Demon in order to function. You may have a similar reaction if you are sensitive to energy or spirits.
Demons need to be trained.. If you have a newly bound Demon, and the summoner didn't train the Demon, you will have to assume that role. The more expensive Demons have been trained and have experience working with humans, but the cheaper ones have not.. You get what you pay for.
The third Demon I purchased was expensive, but he was well trained and gets along well with myself and my spirits. I didn't have any problems bonding with him, and I didn't have any problems with mood swings or other empathic disasters. He is very knowledgeable of our world and how it works, and I rarely have to explain any commands.
Bound Demons come to this world for the first time in their entire lives. They don't know how our society works, and they are unsure what things are and how they work. If you tell your Demon to make sure you get to work on time, they may be unsure of how to accomplish this. You may need to explain how a traffic light works, explain how you must ensure that no cars run into you, and that you are invisible to the police. You may need to explain a lot of things before they are sure of what they are assigned to do. While you explain everything to them, you need to picture your point in your mind. They need to see what a traffic light or a police car looks like.
Not all Demons are exactly the same. Some are partially animal, some are all animal, and some are humanoid. Their level of understanding and their ability communicate varies. I have one Demon that only communicates through visuals, one that will communicate through visuals and some slowly formed words and sentences, and one that is very fluid in their verbal skills.
A Demon is much more maintenance oriented than any Otherworld Entities. You need to give them time to recharge and go home. You need to stay vigilant with new Demons in your home. You need to detect any changes in the energy of your home, detect if they are feeding from you or your family, detect if they are feeding on or attacking your Otherworld Entities, or any strange occurrences that may be related to a bored Demon. If you are unable to detect your Demons, communicate with them, judge their moods, or judge any problems, you can have numerous undesirable outcomes. If you are unable to control and monitor them, you may be faced with many problems.
I don't recommend Demons to new Otherworld Entity Keepers. It would be like a High School basketball player trying to play for the NBA. There is a higher level of skill needed and it is difficult to go from no skills to a highly demanding spirit in a short period of time.
If you get in over your head, you could cause repercussions to your life that may take months to years to clean up. If the Demon is too powerful, and you are unable to control it, you may loose your job, your spouse, your house, or even your health. Demons can be powerful allies, but with the great benefits also comes great risk. If you are willing to take this chance and get a Demon as your first Otherworld Entity, be prepared for the unexpected.
If you believe you can handle a Demon, please find a reputable Demon Master. Binding Demons takes a special individual with a high level of skill. Do some research and make sure you are buying from a well established Demon Master. You want to make sure the Demon is properly bound, trained, and one you can handle. Start out with a low level Demon because they cause less damage and are easier to control. You can work your way up the ranks, and learn to control various levels of Demons. And remember with higher level Demons come greater responsibility and higher risk. Don't get in over your head, or you can have severe and detrimental consequences to your life.