Ethereal - Ethereals of Fio'taun: When the T'au entered their darkest age as the 37th Millennium of the Terran calendar drew to a close, and the entire species was being destroyed by war and disease, many strange portents and omens were observed such as flickering lights in the night sky and half-glimpsed figures in the mountains. Many believed that these were the signs that they were living in the last days, that extinction was nigh.The legend tells that on a mountain plateau called Fio'taun, an alliance of plains dwellers and Air T'au laid siege to the mightiest fortress-city of the builder T'au. Nearly seven thousand beings dwelt in the great citadel and, in vain, the traders attempted to negotiate with the plains warriors. The plains warriors' blood was afire though, and they would brook no settlement save that delivered at the end of a rifle.For five seasons the cannons of Fio'taun held the attackers at bay, but supplies were running low and disease was rife within the city walls. As night fell upon another bloody day of fighting, the leaders within Fio'taun prayed for a miracle. Little did they know that on this night their prayers would be answered.Emerging from the darkness, a T'au of unusual appearance walked into the besiegers' camp, asking to see the army's commander. He was softly spoken, yet it is said that he had an undeniable authority. The sentries to whom he had announced himself found themselves compelled to escort him to their leader.At the same time, within the walls of Fio'taun, a similar individual presented himself to the guards of the fortress. How he had penetrated the defences of the city he would not say. All he asked was that he be allowed to speak to the castellan of the fortress.Again, his request could not be denied and he was permitted an audience with the city's leader. Within the hour, the fortress gates were opened, the stranger guiding the citadel's leaders towards the torchlit camp of their attackers.As the gates opened, they were met by a party from their enemy, led by a figure who was the stranger's twin in all respects. The two newcomers called themselves Ethereals and bade the others sit.Beneath a maiden moon of purest white, they began to speak, explaining that the talents of each of the tribes could be harnessed. They spoke of a Greater Good that could be achieved if they would put aside their warlike ways and worked together.The two strangers talked through the night, their words carrying great power, and as the sun crested the horizon, a truce had been agreed between the warring factions.Fio'taun was just the beginning. Soon, more of the Ethereals emerged and the message of peace and the Greater Good began to spread to every corner of the globe of T'au, the battles slowly dying out as the new philosophy took hold. Within the space of a Terran year, the wars were over and the T'au flourished like never before. Well-constructed towns and cities sprang up throughout the continent, commerce routes were re-established by the traders and communications maintained by the Air T'au.The warriors of the plains were the hardest to convince that this was the way forwards, but as they saw the civilised wonders being created by the other castes, they finally agreed to the Ethereals' entreaties and became honour-bound defenders of the T'au. It was decreed that from that day forth each of the tribes would be known by the element that most befitted its role in the Greater Good.The builders and artisans would be the Earth Caste, the traders the Water Caste, the messengers and scouts would become the Air Caste, while the warriors of the plains would be known as the Fire Caste.Having saved the T'au from a slow species-wide extinction, the Ethereals were revered with utmost devotion by the other castes, binding and guiding them as they looked towards the future with a newfound sense of hope.