Jūsanseiza

The Jūsanseiza (じゅうさん星座, Literally meaning Thirteen Constellations) are a group of shady individuals whom are known to have elluded Soul Society for several centuries, few of the existing members have ever been seen, though it is rumored that their ranks are primarily made up of former members of the Royal Guard whom have gone rogue. Though these remain as simply vague suspicions at this point.

Overview
Very little is known about them at this point other than what was stated before, though given the fact that they're very rarely, if ever sighted it can be deduced that they make their headquartes where Soul Society under normal circumstances wouldn't be able to reach. Its also quite obvious, that as former members of The Royal Guard, each of them possess immense capabilities in their own right.

Their goal is also unknown, though it is speculated that they seek to overthrow Soul Society in some way, or even perhaps assassinate the Royal Family, though those are all just suspicions, once more. And may only be due to the Royalities' well known paranoia.

Members
While none are actually known, or have likewise been proven to be part of this organisation, the following individuals are rumored to be a part of it nevertheless.

Trivia

 * Members are preferred to be between Shunsui and Aizen-Class in power.
 * Every Gravity Force member are allowed to create a character for this organisation, though more than one requires community-wide acceptance.
 * 13 is currently the max amount of members at any one time, though their total number need not be exactly that amount; feel free to make further spots than the current three, if you please.