The Chaos Region 
Here is the flag of the Chaos Region.This flag can be seen flying above the Castle of Might, but pretty much nowhere else. The flag depicts Zapdos, Moltres, and Articuno - the Guardian Legendary Pokemon of the Far Eastern, Desert, and Northern Sub-Regions respectively - as well as Clovquatro, the Guardian Legendary Pokemon of the entire Chaos Region. Here is the backstory behind the design of the flag:
A long time ago, in ancient times, the Chaos Region as it is known today did not exist. Rather, the geographical area currently occupied by the Chaos Region was split between three different regions. They were the Northern Region, the Desert Region, and the Far Eastern Region. These three regions had distinct, different cultures, artistic styles, and army compositions, but one thing they had in common was that each of them had a Legendary Bird as a Guardian of their Region. The Northern Region's Guardian Legendary Bird was Articuno, the Desert Region's Guardian Legendary Bird was Moltres, and the Far Eastern Region's Guardian Legendary Bird was Zapdos. Then one day, three Kings, known as Clovis, Shahatem and Kenryuu, from the Northern, Desert, and Far Eastern Regions respectively, started following the Legendary Birds in the sky, carrying with them an offering from their lands to give the to the Legendaries. The three Legendary Birds then led the three Kings on a difficut journey up to to the top of Mt. Chaos, the highest mountain in the Chaos Region. The extremely hard journey was like a trial of faith, but eventually, all three Kings made it to the summit, where there was a triangular lake known as the Tripoint Lake. Each King then approached the lake, and stopped upon finding themselves standing at the three corners of it. The three Legendary Birds they had been following then flew towards the center of the lake, and started flying in a circle above a large, tall rock that stood out from within the lake there. Standing atop that rock, and below the three Legendary Birds flying in a circle, there was a wondrous, magnificent presence, whose visage left the three Kings speechless in awe and astonishment! It was a large, awe-inspiring peacock-like Legendary Bird, whose form had never before been captured within human eyes! Its feathers were green and leafy, its tail was spread out to display numerous four-leaf clover symbols on it at the areas where a normal peacock's "eye"-like patterns would be, and it had a glittering golden horseshoe-like crest atop its head! As the bright Sun was shining directly above this Pokemon, its spectacular body almost seemed to glow within the intense sunlight! Amazed by its beauty, grace, and legendary air, the three Kings then immediately gave their offerings the peacock-like Legendary Bird, known as Clovquatro. According to legend, Clovquatro then commanded the three Kings to unite together in one Region, so that they may all prosper together. The three Kings then accepted the Legendary Pokemon's instruction, and then Clovquatro flapped his wings and spread some pollen on the Kings, in a ritual to seal the Covenant between them. The three Kings then went on their way, and then, for the next seven generations, their lands saw incredible prosperity, with rich harvests, plenty of success in hunting and fishing, inspirational leadership, many scientific, artistic, and other innovations, and an indescribable sense of faith and inspiration flowing throughout the hearts of the people of the entire united region, which came to be collectively known as the Chaos Region. This period of time later became known as the Chaos Region's Golden Age. The Kings' contact with Clovquatro was said to have brought all these blessings upon the people of the Chaos Region, and so, Clovquatro came to be known as the Good Fortune Pokemon, and seen as the Guardian Legendary Pokemon of the Chaos Region, guiding its people into their common unity and prosperity. Some people also thought that Clovquatro was a messenger of the PokeGod himself, who, long ago, had descended upon the Earth and destroyed the False King who previously ruled and oppressed the entire Earth, ACCLAIM, in the process turning the Desert Region from the lush forest and grassland it used to be into the desert it became afterwards (and hereby granting it its name), by the power of the insanely catastrophic attack he used to destroy the Dragon Master there.