The Ark Arena, also known as the Ark Project, is the central setting and plot point of Chaos Rings and Chaos Rings Ω. It is a system designed by the inhabitants of a doomed world to combat the Qualia.
The Ark is an extremely large spaceship capable of travelling through time and space. The Ark contains several habitable environments, but these are completely artificial and are inhabited by dangerous Congloms, which test the skills of the participants. The Congloms are produced by Cyllis in the subterrean Conglom Plant, deep in the bowels of the Ark. The only area free from Congloms is the Home area, where the participants can rest and restore their MP. The Home area contains a door capable of warping people to the different areas of the Ark and to the outside world. However, the door's operations are controlled by The Almighty, so participants cannot go wherever they want at first and cannot leave the Ark. The Home area also contains rooms for the participants and Piu-Piu's shop. It is also the place where participants battle The Agent (and Piu-Piu, although this is optional). The most important part of the Ark is Bereshith Road at the top of the Ark, where The Almighty resides. Many of the Ark's systems and historical documents are stored here, and the cold-sleep system room (which also functions as a battlefield for the Arena) is also located in this area.
The Ark also has a deck, although it is nothing more than a flat area with designs on the floor and is not meant to be reached normally, unless there is a teleport error when opening the Original Door.
The Ark was transported to a specific point in spacetime, known as the Singularity, where it is possible to destroy the Qualia. However, the primitive human race within this point had not yet developed their latent talents to destroy the Qualia. Thus, the Ark repeatedly travels through the timestream at this point, honing the skills of the humans until they can destroy the Qualia. The Ark gradually improves the Genes of the humans, causing skills such as Magic and Teleportation to appear, by placing them in an environment where their focus and concentration are at their greatest and they learn skills easily. Through this, humanity's best genes are brought forth. The Ark then transports those containing these superior genes back in time 10,000 years, making them humanity's progenitors, so each generation will grow stronger until they can eventually face the Qualia.
The Ark teleports a select group of humans with the most advanced genes from Earth at the moment when the Qualia destroys it. The Ark then travels back into the timestream, and the Ark Arena begins. Each contestant is paired with the person they care for the most, and the four pairs are pitted against each other. The Arena is initially portrayed as a contest of the Earth's strongest warriors, fighting each other to the death. Initially the pairs believe they are fighting for Immortality, but at the end of the Arena, if they are not strong enough to defeat the Qualia, they will gain Immortality and become humanity's progenitors. If they are strong enough, they must face The Almighty and then travel to the Convergence point, where the Qualia will appear.
The Arena is set up in this order:
1. Contestants first arrive on the Ark and are told to retrieve the Warrior's Ring and the Companion's Ring. They do so by travelling to locations within the Ark and facing powerful beasts guarding the rings.
2. The first battle to the death. Each pair is matched up with another, seemingly randomly, and the two pairs must battle to the death. During the battle, the winning pairs will gain the Genes of the pairs they defeat. The losing pairs are not killed by the winning pairs; instead they are killed by the Executioner.
3. The two surviving pairs must then obtain proof of their partnership. In order for this to happen, they must strengthen their emotional bonds, and defeat two more powerful beasts within the Ark.
4. Even if one pair does not obtain their proof, the next battle will proceed. Once again, the Executioner will finish off the losing pair, and the winning pair will get their genes.
5. The final pair either become the First Couple, if they are not strong enough to face the Qualia, or the Final Couple, if they are strong enough.
5a. First Couple: The winning pair defeat the Agent and leave through the Original Door to Earth, 10,000 years in the past. They are granted Immortality and told to become the progenitors of humanity. Some of the truth of the Arena is revealed to them. They or their children will take part in the next Ark Arena.
5b. Final Couple: The winning pair, after beating the Agent, are granted access to Bereshith Road. There, they will find documents revealing the history of the Ark Arena, and must defeat the Executioner and the True Agent. At the top of Bereshith Road they will face the Almight, who will tell them of their mission. After defeating her the portal to the Qualia will open.
Due to gradual exposure to the Qualia, the Ark began to break down. By the time of Olgar's campaign, many non-vital functions had shut down, such as lighting in the Home area. Eventually, the Ark was consumed by the Qualia, but some vestiges of its time-travel power and Theia's consciousness remained. After the defeat of the Qualia at the hands of the four Final Couples and their descendants, Theia's consciousness transported them back to the time and place of their choosing (although all chose to go back where they were right before the events of Chaos Rings) and shut down the Ark's functions, ending it once and for all. The founder of the Ark Project, Piu-Piu, escaped the Ark's destruction but lost his memory and ended up on The All-Seeing Eye, in a universe that the Qualia had destroyed.