Before the game begins, the planets Remuria and Mutras had already been at war so long that weapons development crossed into Organic Weapon Production fused with alien technology. The result was Brawshella — a sentient weapon that subjugated all animal life on both worlds and assimilated most of humanity within a week.
Assimilation brought no peace. The absorbed population kept fighting each other out of old habit, purpose erased. Six former fighter pilots eventually broke free of Brawshella's control, reclaimed their identities and memories, and chose rebellion over obedience — mounting a final campaign to destroy the machine and reclaim their devastated worlds.