User blog comment:Xilinoc/Ch. 685 - THE PERFECT END/@comment-24726378-20160804153727/@comment-27001684-20160804162204

I think Rukia is a better leader than Renji, while the latter was capable of using Bankai (incomplete one) before her, he doesn't appear to have greater leading skills than Rukia.

He also wants to surpass Byakuya and most likely because of this, stays as a Lieutenant until Byakuya resigns, wanting the latters position.