Plot
The game begins with two men talking about the nearby vampire's ability to control flame. Lucian, the Lunar Knight overhears them, and sets out to obtain the whereabouts of the Duke, the leader of the Dark Tribe vampires. Later in the level, Lucian encounters Bea, a solar gunslinger attempting to free the prisoners of the mansion. Lucian realizes the strength of the vampire, and must upgrade his weapon by taking it to Professor Sheridan. After a confusing moment with the Professor's maid, Lucian barges his way in.
Returning to the Mansion, Lucian refuses to help Bea free the prisoners, claiming they would not even try to fight back against enemies. Lucian blocks a bolt from the vampire meant for Bea. After defeating and purifying the vampire, he obtains the power of the flame terrenial Ursula. He also discovers that to reach the Duke, he must collect the other three main terrenials.
The guild is attacked and Aaron, the Solar Knight, is told to warn the other members. When he escapes, Aaron sees a girl on an opposite rooftop being chased by undead. Aaron fires his gun and destroys the undead. Aaron obtains the power of Toasty, the Solar Terrenial. Later on, two vampires known as the Poes attack Aaron, but Ernest, the Leader of the Guild, and Kay, his apprentice, distract them and Aaron must gather the last of the members. Aaron fights the Goat Chimera and Bea appears to assist Ernest and Kay.
Aaron is worried about Ernest and Kay. Bea reappears and tells them the vampires are hiding in the sewer. Bea calls Lucian, and while Lucian refuses to let Aaron come along, Bea ignores him. When they arrive at the end, The Poes reveal that they have packed the gunslingers on a train for the vampire tower. After defeating and purifying the Poes, Lucian and Aaron obtain Alexander and Tove, terrenials of Wind and Earth. They must now infiltrate the train station. Arriving near the end, Kay reveals that Ernest distracted the guards. Lucian finds the Duke and attacks him, but he teleports away. The player boards the train and begins to make their way across the train. On the way across, a pink orb flies by the player, and a conversation with the mystery immortal known as Polidori begins with Stoker. The player defeats and purifies the vampire known as Baron Stoker.
Lucian and Aaron fight their way into the city, and eventually reach the Dark Castle. Before entering, Polidori appears to them, explaining he is an emissary from space on behalf of the immortals. Lucian and Aaron travel through the castle, and discover that the enemy pilot they encounter in space during purification levels is Perrault, Nero's other half. The terennials question their goals and wonder if their battle is right, eventually deciding that the humans are smart enough to save their world, the duo find themselves in the throne room. After defeating the Duke, Polidori absorbs him, informing the duo that the ParaSol was really the Planet Eater, a planet-destroying weapon.
Lucian and Aaron make their way through the Planet Eater up to Polidori. After beating him, Polidori flees into space, where in a 4-Part battle, he is destroyed. Perrault rescues Lucian and Aaron and the credits roll.
There is a postgame bonus level named Vamberry, a 100 floor tower. At the end of it, Lucian and Aaron defeat the resurrected Polidori. During the levels, the two discover that Dumas has also been remade by Perrault. Polidori's aims are questioned by Lucian, who accuses him of being only a copy of the real Polidori. He states that he understands the aims of the real immortal. The Knights defeat Polidori, and Dumas appears to tell them that the Immortals will arrive to stop the renegade Earth. He tells them that Humans and Vampires may have to become allies. Dumas leaves, and Lucian declares he will never work with Vampires, even against the immortals. The scene ends with Aaron unsure Lucian will hold to that promise.
