Demonic activity worldwide has significantly increased due to the involvement and corrupt practices of the Illuminati. To combat the unnatural influx of demons, the Vatican Headquarters decides to hold the annual Exorcist Certification Exam early and allow for as many exorcists as possible to take up the mantle. Straight from the Vatican, one of the most powerful exorcists, Lewin "Lightning" Light, arrives at True Cross Academy to help prepare the students for the exam. The ease and mastery with which Lewin performs exorcisms quickly impresses Ryuuji "Bon" Suguro, who has lost his ambition to continue his studies, and Lewin surprisingly accepts him as his apprentice. Amid the worsening situation, twin brothers Rin and Yukio Okumura are sent to locate the recently missing exorcist Shura Kirigakure, who seems to be chained to a decades-long contract with a powerful, immortal demon hiding in Aomori Prefecture's dangerous, snowy mountains.

Even though the Decepticons have been driven off Earth, a small team of Autobot Pretenders have remained behind, just in case. Led by Metalhawk ("Hawk" in his human identity), the Pretenders live among the humans, using their Pretender shells to assume human size and appearance. The Autobots' caution is rewarded: Decepticon Pretenders soon appear, led by a mysterious force called Devil Z. The Autobots and Decepticons soon build up their forces, recruiting humans to become Junior Headmasters and Godmasters (Powermasters).

The planet Libertia was once known as “the planet of death”, until humanity built three giant mirrors and created what seemed like an ideal land. It is on this planet that Professor Grace and his granddaughter Alcia live peacefully… until their home is attacked by Guild soldiers looking for the professor and for Legaciam – a special Armor that can resist extreme heat, allowing it to go to areas where humans would not survive normally. Alcia, who was at the time piloting Legaciam in order to help her grandfather with the testing, manages to get away… barely. But the Guild is determined to get Legaciam by any means necessary…

The world is a dark, brooding place populated by humans, but ruled in reality by powerful beings known as the Darkstalkers, and there is constant conflict between them as they try to determine who is the most powerful of them all. Zombies, vampires, werewolves - all of them compete in contests of strength and sheer will to attain their own personal goals. All of this becomes moot when a race of Aztec robots called the Huitzil decide that humanity isn't worth saving, and start waging war on the world, while in the sky, a solar god from outer space plots the conquest of Earth. And the Darkstalkers must become unwilling allies in order to save the world.