What kind of institution is Gotei 13? Authority? Justice? Policy maker?

Question

According to Wiki:

According to Yhwach, the original Gotei 13 were "defenders" in name only, comprising nothing less than a brutal mob of killers, but it was for this very reason they were a force to be feared, especially because Yamamoto was a ruthlessly pragmatic leader whom would hold even his subordinates as expendable. It is noted the Gotei 13 underwent dramatic changes after the extermination of the Quincy, mellowing out in the ensuing peace, having now found a sense of justice upon discovering things to protect and treasure.

Does this mean Gotei 13 is acting as private organisation in Soul Society or is it an authority or law maker than can judge souls. If Gotei 13 is govermental authority, How can they exterminate Quincy if they act on behalf of Soul King? I know Soul King doesn't directly control Soul Society. And I believe what Gotei 13 has done was unjust. Therefore, I conclude that Gotei 13 is not ultimate source of justice. Therefore, every soul can do whatever it wants in Human World, Soul Society, or Hueco Mundo without disobeying anything since authoritive figure doesnt exist among souls.

I believe the only thing that makes Gotei 13 an authoritative institution is because they have group of Bankai users that are willing to punish other soul on behalf of Yamamoto.

Answer 1

The Gotei 13 was mainly used to keep the control and order in the Soul Society. They are also the first line of defense from any enemies, such as Hollows, Quincies, etc. They maintain the balance between the spirit world and the real world by eliminating Hollows, and guiding lost souls.

The main purpose of the 13 was to provide an authoritative sense. Hope this answers your question.

Answer 2

The Gotei 13 is a military organization in the Soul Society, together with the Kidō Corps and Onmitsukidō. They are not a private military organization, which is not loyal to one government, since they are loyal to the Soul Society.

If Gotei 13 is governmental authority, how can they exterminate Quincy if they act on behalf of Soul King? I don't quite understand why acting on behalf of the Soul King should have not made the Quincy extermination possible in the first place. From the wiki:

The Soul King is not involved in governing Soul Society, having given the full control of its government to the Central 46 and thus being uninvolved with the day-to-day affairs of Soul Society.

He is, however, seen as a king since he has probably the most important job of all. To quote again from the wiki:

The Soul King's sole purpose is to regulate the flow of souls into and out of Soul Society and keep the flow stable. Without the Soul King, the balance is lost and everything that is linked to Soul Society or made in it, as well as the Dangai, Hueco Mundo and the Human World will fall apart.

The Gotei 13 was forced to exterminate Quincies since they were making the cycle of souls unstable.

I also believe what Gotei 13 has done was unjust. Therefore, Gotei 13 is not the ultimate source of justice. Yes, it was not morally right. Were they fair? Probably not. But both sides are at fault; the Quincies, for not listening to the Shinigami that they endanger the balance and the cycle of souls and the Shinigami, for only seeing themselves as the ones who should only have the job of handling souls and hollows and not compromising with the Quincies so they can work together.

However, the Shinigami still did their job to maintain the flow of souls with this.

Therefore, every soul can do whatever it wants in Human World, Soul Society, or Hueco Mundo without disobeying anything since authoritative figure doesn't exist among souls. With this, you just denied the existence of the Soul King, the Central 46, the Royal Guard, the Gotei 13 and every other authoritative figure in Bleach. Unless these organizations cease to exist, every actions done by souls against the law would have a consequence.

That the Gotei 13 committed acts which, to you, is unjust does not mean they are not authoritative, or that other branches in the Soul Society government should be branded as the same.