NakeBenihime said:
I want Aizen to return, but what does his return have to do with Central 46? Aizen was last seen in Muken, which is located beneath the Squad 1 barracks.
You forget that Central 46 is pretty much the governing body of Seireitei. Thus they should have the only authority of releasing criminals from out of Muken. Shunsui is merely the military commander of the armed forces (Gotei 13). As I understand it, their influence and jurisdiction exceeds his.
That said, Aizen returning may very well still be wishful thinking on our part. Perhaps Kyouraku is simply heading over to the Daireishokairō to investigate matters regarding the Oken since old man Yama most likely never passed on the knowledge of its whereabouts to anybody else before his untimely demise.