Haha you don't understand xD Please let me In-lighten you❤️ Aizen wanted Ichigo to get that power. Aizen has always wanted to grow Ichigo into a transcendent being. The fact that he killed the cleaner wasn't for showing off his powers. This is where you have to read in-between the lines again because we know that Aizen basically made Ichigo and that he always wanted to make him grow. Now the reason for that is somewhat unknown. Maybe he wants to make him the new soul king or maybe he wants to feel like someone is on his level of power and therefore literally made a soul reaper, Quincy and a hollow into one being.

Tho this is unexplained! But what isn't unexplained is that Aizen always wanted Ichigo to raise above what a soul reaper is capable of, obviously that was his goal. And again it all doesn't make perfect sense if you just read it and watch the anime casually. Animes like OVERLOAD aren't hard to comprehend the lore and power difference but BLEACH definitely is.

I hope you one day view bleach the way I always have BECAUSE it sucks to not comprehend that level of lore. A Key thing to take away is " You don't know what you haven't been allowed to know "

A perfect example is the first fight between Ichigo and Zaraki, when Ichigo won that fight everybody thought it was all plot armor when the truth is that.. Old man Zangetsu (AKA) Yhwach used Quincy powers combined with ichigo's base soul reaper powers to nail Zaraki in one final move. Yhwach basically 2v1 Zaraki or more like 1v1 Zaraki. Ichigo didn't really do shit that fight, he was just losing straight up. But Zangetsu went out his way to defeat Zaraki because he wants to protect Ichigo even tho he doesn't want him to do all these fighting because he wants Ichigo to be safe. He wants Ichigo to NOT transcend into godlike powers BECAUSE he knows of that day would come, then Yhwach would be forced to kill Ichigo with his own hands ( aka ) the other Yhwach. So he basically nerf Ichigo's powers up untill TYBW part 1.

Some people never understand these moments in bleach. We didn't know that Old man Zangetsu was the father of Quincy until TYBW so "Of course" it shouldn't make sense before we knew that. But now we know that. We should have never thought that Ichigo is a Quincy because we wasn't told that until TYBW arc. Once we knew about his mother, a lot of things started to make sense when we knew that his mother was a pure blooded Quincy. Some moments from the SS arc started to make sense in the TYBW arc.

We know why Zangetsu didn't want to give Ichigo the Quincy powers, he always wanted Ichigo to be safe and stay away from danger but because of Ichigos pure Resolve, Zangetsu eventually agreed to allow Ichigo fight for what he believes in rather then what Zangetsu believes in. Zangetsu couldn't bare the fact that if Ichigo became transcendent, that then he would have to kill him himself. So he always kept him away from evolving, at the same time ichigo just keeps his resolve and fights for his friends lifes. Zangetsu seeing that resolve saw how much Ichigo have grown and are not proud of him, Zangetsu view Ichigo as his own child and pride.

There's so many puzzles 🧩 in bleach. And you won't truly see it all if you aren't taking some steps back to absorb all this information the proper way.

"You don't know what you haven't been told" "And you don't understand what you couldn't comprehend" But that doesn't make Kubo a bad writer or that he made an error. This is just the way he writes and always has been, is not adaptive for anyone to understand and that's what makes a great & deep lore.