We have a glimpse at Shunsui's true personality now - a nihilistic, uncaring, dark individual who seems have lost all hope for the world: a lifeless abyss indeed.
Truly an impressive chapter, this Bankai could've most certainly posed a major risk on Aizen's well-being given its absurdly powerful abilities, at the risk of many others within FKT.
Prepare for a lot of flashbacks next chapter, however. I hope to see Starrk in Shunsui's consciousness, they're both more connected than I imagined. Shunsui didn't seem like a lonely type of person until this chapter came around.