Petropolis A

Petropolis A (ペトロポリスA) is an RPG developed and published by Namco. The game primarily focuses on the events surrounding the attack on the Miracle Kingdom and the disappearance of the Sacred and Great Orbs before moving on to follow the cast of characters across two dimensions as they encounter a new ally, Pearl, and seek to stop the invasion of their world by Nox, the leader of Pearl's clan, the Midnight Clan. It was the first and only RPG game in the Petropolis series, and only released on the Nintendo DS.

Plot
One day the Miracle Kingdom gets under attack by a mysterious group calling themselves the Midnight Clan. Quake and Pyro try their best to protect the Great Orb, but they are overwhelmed, and they call upon the help of Team Black and the Garage Kids to aid them.

The heroes arrive at the Miracle Kingdom and help the dragons fight off the Midnight Clan. When unmasking one of the commanders, they are revealed to be dragons as well. They question one of the captured Midnight dragons, Pearl whom explains their history: The Midnight Clan was warring with the Sacred Clan eons ago but a warphole to another dimension opened up and pulled them in a world called the Twilight World. She and the rest of the clan now want to return to the world of their ancestors, but lack the means to bring all of their clan back, their dimensional breacher only working for a few.

Though when the heroes take their prisoner to the Dragon Shrine, they meet the leader of the Midnight Clan, Onyx, who goes by the alias Nox, the enigmatic Doctor Aether and Pearl’s sister Agate. Nox reveals he not only wants to merely return to Earth, but also conquer it. Pearl refuses to be part of it and turns on the Midnight Clan. But as the heroes fight against the Midnight Clan, they, along with the Sacred and Great Orbs, fall into the Twilight World. Now, the heroes must search for the orbs and free the other clans trapped in the Twilight World from the Midnight Clan’s slavery.

Playable

 * Thunder Storminski
 * Julie Vixen
 * Fluff Cotton
 * Aaron Clawface
 * Rick Ogami
 * Walter McBlowhole
 * Tusk Woo Lee
 * Chippy Nutcheeks w/ Miyu
 * Grace MacGryphon
 * Whirlwind Spinner
 * Selene Melodia
 * Crugg
 * Mars Stanford
 * Monday Fernandez
 * Betsy Spots
 * Gloria Glass
 * Yoshino Kaneko
 * Miné Crystals
 * Pyro
 * Quake
 * Pearl: the lieutenant among the Raiders, and the head of intelligence within that organization—essentially a super spy. She has lived within the Twilight World with others of the Midnight Clan these past millennium and her job has been a challenging one, given so many rival factions constantly vying for supremacy. After realizing that Nox has been deceiving her, she joins Thunder and his partners in an attempt to stop him.

Antagonists

 * Nox: an ancient and evil dragon who was originally Pyro's great-uncle Onyx, who became Nox after being banished to the Twilight World along with the Midnight Clan. With the assistance of Dr. Aether and Agate, he plans on returning to Earth, only to capturing it as well. After his ambitions were revealed he was stopped by Pearl, Thunder, and the dragon brothers. It was revealed that Nox is the name of a being from the Twilight World who has been pulling clans in to find a suitable vessel through which he can survive outside of the Twilight World and that Onyx was merely possessed.
 * Agate: the abusive sister of Pearl. She and Dr. Aether sided with Nox, believing his ideals on returning to and controlling Earth. Due to her reliance on Nox's conquest ideals, she became obsessed with the idea of liberating the beastmen of Earth, turning them into her slaves. Pearl tries to reason with her sister, but Agate supports her leader's vision and the sisters fight, the former being forced to kill her sister in the fight.
 * Dr. Aether: a dragon scientist who gained corrupted sacred powers after being sent to the Twilight World. As a result, he took on a drastically altered appearance: pink-scaled with red eyes and black sclera. Driven to purify the "corrupt" Earth, he joined the Midnight Clan in order to learn more about sacred power by studying Onyx. Dr. Aether then reveals his true colors, and drains Nox's essence from Onyx, and uses it to power himself up, only with his mind intact. He then reveals that he not only wants to conquer, but outright destroy Earth and recreate it, as he finds the old world ‘corrupt’. The Super-powered Aether puts up a good fight, but with the power of the Sacred Orbs, Thunder, Selene, and the dragon brothers destroy Aether and Nox. Onyx, dying due to wounds inflicted by Aether, asks for forgiveness and in his final breath makes Pearl the new Midnight Empress. She returns the Midnight Clan back to Earth and settle on the Miracle Kingdom, and decide to peacefully co-exist with the rest of Earth. Due to bonding throughout their journey, Pearl and Quake also become a couple.