Pact: Noun: A binding alliance or treaty. Usually intended for the long term, or until all set goals have been achieved.
Observer: Noun: One who witnesses events.
In this world, it is possible to attract the attention of beings from outside it. One side effect of this is to allow feats that would otherwise be impossible, so long as they fit within preset parameters, which can be defined by any form of communication. The only beings capable of being reached have been dubbed Observers, as that was all it was known they could do for some time.
It was eventually discovered that Observers could take control of a willing host, so long as that control was both well defined and freely offered, and in the process it was found that Observers were not bound by time in the same manner as anything else in the universe-they frequently displayed foreknowledge of events beyond all but the most precise forms of omniscience, and their skill or preferences could vary dramatically during a task, but they would always succeed eventually. This was taken to it's logical conclusion when the man who discovered all this decided to make a Pact to take over his country, and ended up leaving enough destruction in his wake that most knowledge from that era was lost. In the chaos that followed, Powers based on those granted by Pacts were developed as a much safer alternative, various systems to suppress Pacts developed similarly, and the world still faces at least one major catastrophe per century.
Welcome to the Observed Universe.