These are the different groups/alliances in Kiijutsu. you do not have to have you character be a part of one of these, and very many aren't. you are free to just be a citizen.
The Empire
Those who are officers, relations, etc. tp the emperor. The usually live within the temple walls. most are loyal to the emperor, though there are exceptions.
The Musou
The Musou are a group of rebels led by Kaiyira Uegaki. They are set on having the world the way it was before the reign of Ryoko. They miss the happy ways of the lands. They want to win this battle with as little bloodshed is possible. They are open in their rebellion, and the Emperor is fully aware of the Musou organization. They despise him, and he despises them.
The Reika
A group of scientists who study the DNA and abilities of angels. They are quite a mixed group. They are not for the emperor, but not against him. They are more for themselves. Some study angels to harness their power, wanting the empire for themselves. They are merely powerhungry, with the advantage of intelligence. Some actually do have somewhat good intentions. They want the empire to be demolished, and life to return to how it was. happy, and with technoligy and medicine. Both sides to the Reika, though are similar in the fact that they don't care who dies, or what they have to do to win. The emperor is not aware of the true intentions of the Reika. he thinks they study angels for his own benefit, so he aids them with money, and lets them be.