This technique becomes available only after Vyse becomes captain of the Delphinus, but even then, there are several requirements needed to make the option appear during battle. Using Prophecy requires a full SP bar, completely maxed, to even have the ability to select the technique (which appears in place of the Run command). The party must have four members on the battlefield, (so it is temporarily disabled once Enrique leaves) and all members of the team must be both alive (not unconscious) and controllable. If a party member is negatively afflicted with the Sleep, Confusion, or Stone status, he or she is no longer controllable. If one or more of these requirements are not met, and the player still achieves a full spirit bar, Prophecy is disabled but the Blue Rogues Crew Special Move remains usable (provided that Vyse is controllable).
When Prophecy is triggered, all party members lose their individual attack phases, however, after the move is executed all surviving opponents lose their attack phases as well. Prophecy is an Expedited Ability, which takes effect before any and all other abilities by any combatant on the battlefield, and in this case causes all combatants to "lose a turn". Using this ability will completely drain the spirit bar to 0.
During the execution of the move, the party combines all their battle energies in a plea for assistance by "the ancients". The result is that one of the moons is pulled down from the sky where it crashes into the battlefield and/or planet, causing large amounts of battle damage to all foes.