The order has been keeping the world from being completely overrun by demons for a very long time now. There is a very specific demon clan that comes from another planet and has been looking for ways to get people enslaved. They are out to conquer planet Earth completely. They are from a planet that is light years away from our solar system, but they actually have the power that are required in order to travel great distances in a matter of seconds.
The order had to stop these demons with the powers of another alien species that has been at war with those demons for centuries. The order made a deal with this alien species and they agreed to help human kind as long as another planet that the order owned was delivered to them. The order agreed because that planet wasn’t as useful to them as Earth.