Kl.ō was one of the four major Houses in the Xi'an Empire (SaoXy'an) involved in the Great Divide. When the last daughter of Kl.ō attempted to defect to House Uai'i, a move that would have ended her family line, a war broke out between the Houses. In the final year of the war, the Kl.ō forces were severely depleted; defeat appeared inevitable.
Facing the possibility of their House's extinction, some members of House Kl.ō attempted to assassinate the leadership of houses Uai'i, Ru'a, and Chii by poisoning the air directly above peace talks on RyiXy'an (Hyoton III). Their act of sabotage accidentally started a chain reaction throughout RyiXy'an's network of antique weather manipulation satellites that contaminated the entire planet’s atmosphere, resulting in the death of millions and rendering the Xi'an homeworld uninhabitable. As penance for their actions, House Kl.ō voluntarily chose not to continue their family line. They died out roughly 100 years after the end of the Great Divide.