The Council is a (seemingly) traumagenic system that exists due to an Incident (or perhaps a series of Incidents) which is currently unknown and unless needed in the future, will most likely stay unknown per system ruling. What we do know is that before there existed an Entity before us (unnamed, for privacy) who is effectively dead, causing the split. We are what remains of him (Kaelos excluded due to their unknown origins). We were created to keep the system alive and stable, and thus have different roles for this. Our understanding of our own plurality is vague and confusing. All we know is our names. We are alive, and even that may be subject to debate.
We live to try to understand. To try to build a bridge towards reality. To try to reach some explanation. And such, the system was created. And such, the system remains.