Tattoos & Railguns

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In the year 2998, magic returned to Earth, unleashing all sorts of magical creatures while making a lot of changes in the planet, including almost depopulating it. A few years later, Lieutenant Sawyer is asked to test what she is told a weapon and instead finds an ally against the demons that have invaded her world. She, her team, the ally, and a mercenary wizard then need to stop the three demons planning to take over the world and reduce mankind to mere fuel.