What Do I Have to Feel Guilty About?

The earth fell, the new era ended, and the solar system became a cold cage. The red desert of Mars is forever covered in cold dust, and the four major kingdoms are at war. The nobles hold original sin and blood curse in their hands, looking for the super-ancient weapon of Mars (Deuteronilus). In order to get rid of the depletion of resources and the collapse of civilization, the era of giant ships is over, the Jupiter Federation and the Venus Holy Alliance launched an extreme individual soldier plan Mars' technology is incomplete, but it possesses the power that destroyed the earth thousands of years ago. After countless transformation experiments, "Fluid" finally created the semi-extreme individual soldier "Ling" who can initially control this "fluid". She was controlled by shackles, stripped of her humanity, and turned into a killing weapon at the mercy of others. Until he met Kai, the only pure native human being left in troubled times. All members are prisoners of fate, burdened with sin and shackles. Sinking, fighting, betrayal, and obsession spread across the star sea. When the whole world forces them to sink into the abyss, all those who sink have only one question left: What do I have to feel guilty about?