Here's my theory:
Once, there was a great empire. They were known as the Risen. They were ruled by one king, who had 5 sons. They lived somewhere nobody knows, of which the Fallen do not speak. Then, before the collapse, the darkness visited their world. The Risen, a noble race, rejected the darkness' offer of power. The darkness, enraged, killed their king, and mutated the entire race, adding two extra arms, and changing their faces into unspeakable horrors. They were left with no king. The 5 sons argued amongst themselves, and in the end, split into 5 houses: Judgment, Devils, Winter, Kings and Wolves. Each house gained many followers, with the Devils and Winter with the most. Judgment was the weakest house, and their Kell (the son) died early on. Battered and bruised as a house, the House of Judgment, after our solar system's collapse, seemed refuge with the queen. But from the journey, many Judgements were weak and ill, dying soon after arrival. Soon there were only a few left. The other houses discovered where they had gone, and all followed suit. The Wolves grew powerful, and decided to kill those with which the Judgment House had taken refuge. The queen struck down on the Wolves, and captured their Kell. The Wolves had two choices: bow before the Queen, or face exile. Many were exiled, and set up base on the moon : The House of Exile. The Devils chose Earth, but did not expect any life to be on it. They fought at Twilight gap, but were left to descend into what is now know as Devil's Lair. Saint - 14 managed to kill their Kell, and Sepiks Prime took leadership. The Winter House took Venus, and set up their base in the Ember Caves. They needed a strong soldier, so they raided the Prison of Elders and managed to get the Wolves' Archon; Aksor, the Archon Priest. The Kings set up a small base near the Earth Skywatch, and started to realise that they were sitting near a great Power: Rasputin.
That's it so far, will update later.