Origin (万物归一会) is a secret organization similar to the one led by ‘Tree Shepherd', except they are even more mysterious than the latter. The high level members in this organization are able to sense each through an ‘Ouroboros’(衔尾蛇) ring. Once someone dies, the members would immediately know and choose a new person to replace them. They would then mercilessly hunt them down for revenge.
When Saint Orso overturned Aouine, Origin was already present. No one knew what their goal was, but more than half of the in-game high level missions were related to them. Brendel (Sophie) had a difficult time in the end game because he had also killed one of the high ranking members back then.