Complex sentence: The Monks, occupying the pyramid, cause every clock in the world to display the time of the Doomsday Clock, and offer humanity their help to stop a pending cataclysmic disaster, but only if they "consent".
Split into simpler sentences: The Monks, occupying the pyramid, cause every clock in the world to display the time of the Doomsday Clock. They offer humanity their help to stop a pending cataclysmic disaster, but only if they "consent".