The phase in which all restrictions drop and every faction may attack every other without limit.
Cascadia's combined broadcast announces that Open Hostilities begin soon, telling crawlers and fighters alike that she does not care what any of them do anymore, that she just wants it to end, that she hates all of them, and to get out there and kill. A 90 Second Warning follows, then the system declares "Here we go, bitches! Let chaos reign!"
The phase opens with everything at once: Reaver missiles with advanced seekers hunting the cloaked Party Planner, long-range magical artillery from deep in Dream territory firing rounds far bigger than the previous phase, and The Dream mass-teleporting battalions to the FUPA. Operation Ruin launches into it.
The unrestricted final combat phase of Faction Wars that Operation Ruin is timed to.