Kubo seems to be back on track with making well-paced chapters again.
So we "learn" Isshin was a Shiba (we already knew that, but it's nice to have confirmation).
We learn that around 50 years ago (because I can't count) years ago Rangiku was already a lieutenant and Hitsugaya was the 3rd seat and still looked as expressionless as ever.
Presumably, the incident they were talking about is related to the events leading to the exile of the Visored, Urahara, Tessai, and Yoruichi.
Apparently, Ichigo is (surprise surprise) a unique individual, being the only Shinigami ever to gain his Zanpakutō without using an Asauchi. However, I do find it interesting that on some level, this makes all the Shinigami somewhat equal, as everyone used the same method to gain their blade. Except Ichigo. Stupid plotkai Ichigo. Also, Nimaiya knows the location of every Zanpakutō ever. Which is kinda creepy but cool at the same time.
And finally, Aizen's gonna play a role in this flashback.
Also, confirmation of Isshin as former 10th Division captain, so no more speculation is necessary, and we finally have events closer to the TBtP years of the manga in...well, an easier to read place. TBtP was one of my favorite arcs, and returning to explain the years after it makes logical sense, since apparently everyone's past will be important in this arc. Turns out I was wrong about the nature of Rangiku's important past (I had thought she has helped out Yhwach or something), but whatever.
Overall, a really good chapter hitting all the good points it should. Hopefully, Kubo can continue this trend with his subsequent chapters.
(Note: Fixed the whole 110 years ago stuff, since apparently I can't keep track of time. Thanks to all who pointed it out to me.)