The year is 2079 in the near future.

As humanity achieves technological breakthroughs in overcoming the barriers of biological genetics, Stardust Biotech secretly initiates the “T-7 Symbiote” experiment under the guise of “curing intractable diseases.” Their goal was to fuse human cells with the genes of an unknown extraterrestrial lifeform to create “Super Soldiers.”

However, the experiment spiraled out of control. The symbiotes began eroding humans, transforming them into “Distortions” (aberrations)—grotesque monsters that lost all reason and became violently aggressive. To cover up the truth, Stardust Biotech blockaded Blackrock City, where the research base was located, and deployed mercenary forces to “purge” any survivors.

Ella’s younger sister, Ria, was a core researcher at Stardust Biotech and the only person who knew the formula for the experiment’s antidote. Right before the blockade, she sent a distress signal to Ella, but her whereabouts have been unknown ever since.