On the planet Uni-5, The Horde, an army of murderous robots are invading. The cause? The heart of the beast, an orb that is blue and see-through. It controls the robots ordering them to destroy all beings of flesh in their path. But who is there to defend Uni-5? The Anti-Robot Corps, wielders of the ARC weapons. ARC weapons are infused with Acitorium and made to be extra durable against the robotic hardware. Though not just any normal person can use ARC weapons as they have to be trained and already have a natural talent for controlling Acitorium. They use these weapons to kill The horde, and among them, there are four people who are the most skilled at their craft, the ARC-M (Anti-Robot Corps Masters). They are the most powerful wielders of the ARC weapons.
"But who are we going to be following in this story?" You may ask. Grey, one of the four ARC-Ms. He wields the Sealing Sword. This sword is different from other swords, as it requires a vessel who can challenge the gods. Grey instantly became an ARC-M when he tested the sword and became its wielder. He must defeat The Horde or be its victim.