The G-Man from Half-Life. A seemingly immortal dimensional altering entity who is contracted by a certain set of "employers" and works in mysterious ways. Can put special people in stasis and use them to handle certain tasks. Hops between worlds. Can appear human, but isn't.
What's the plausibility that our world is being shaped by entities like these? Have you ever had an experience with one of these shadowy beings? Shapeshifters? Are they connected to religion?