About Ichigo's Zanpakuto in the final battle & how it appeared in the one-shot...
This is something that I have been wrapping my head around for quite sometime but I always fail to form a clear cut conclusion and get stuck. So, I need your help and please endure my yapping session.
I will start with one of Kubo-sensei's statement -
KlubOutside A277. 01.10.2022 -
The correct form of a Zanpakutō is one that has a sheath, and there are only two swords without one: Sayafushi and Zangetsu.
So, Kubo sensei is stating that a Zanpakuto must consist of two things: a sheath & a sword. The only exceptions were Zangetsu and Sayafushi. Sayafushi was too sharp that Nimaiya wasn't able to make a sheath for it and in case of Ichigo's, throughout the entirety of the series till TYBW he hadn't discovered his full power thus, he didn't have a sheath. But later when he discovers his true power and has two sword one of his blades acts as a sheath thus, fixing the problem as stated by Kubo sensei.
KlubOutside A277. 01.10.2022 -
What fixed Zangetsu into its “correct form” is the dual swords state, and in Bankai Zangetsu is placed back in its sheath, what emerged after that sheath was shattered is the “True Zangetsu”.
Now here is what I think -
When Ichigo activates Bankai he is basically sheathing his Zanpakuto with the action he performs.
I here think that by doing so his Zanpakuto becomes 'complete' as all of his powers from different races has been accumulated in a single blade. His sheath & sword becomes one and by doing so he makes his complete Bankai.
Now when Yhwach towards the end chapter breaks the white portion of his Bankai he is basically breaking the sheath and the blade lies inside the sheath exposing it.
After this Kubo sensei reveals that Ichigo was able to absorb the broken sheath of his Bankai as it is inherently his power. Thus, he gains back all of his powers after the battle.
KlubOutside A277. 01.10.2022 -
The shattered sheath was absorbed by Ichigo
Later in the one shot it is revealed that Ichigo is using the Zangetsu which resembles the shikai Zangetsu from initial arcs of Bleach.
My theory is that this is Ichigo's sealed Zanpakuto that has taken the appearance/form of his shikai Zangetsu from the initial part of Bleach. I am saying that this is his sealed Zanpakuto because of this line stated by Byakuya -
"There may no be any such thing as permanent release."
My theory is that Ichigo throughout the series didn't have control over his power entirely. His power was being controlled/being limited by Old Man Zangetsu. So, OMZ kept his Zanpakuto always in a released state mainly his Shikai which we have seen till TYBW. Now that towards the end of series Ichigo has gained full access/control to his power he can't anymore keep his Zanpakuto in shikai state for all time. He keeps it in a sealed state that appears to look identical to his 1st shikai and upon releasing his sword he reaches the two sword form again. After enabling Bankai from his Shikai he merges his both swords making it his complete Zanpakuto which consists of both sword and sheath.
Now, some questions that may arouse from my theory and my hypothetical answers for them -
Q1. Why doesn't Ichigo still not have a sheath in the sealed state like other Shinigami's?
Ans. I think this is because both his sheath and sword represent his powers from different races. It is Ichigo's Zangetsu's ability that his sheath is combined with its blade in a sealed form, then it separates itself from the sealed blade in shikai making another blade(which acts as his sheath), then when he goes Bankai the sheath properly surrounds the blade. It is opposite to what happens with the normal shinigami's where there sheath houses there blade in sealed state. (Ikkaku can be considered an exception in this case as his sheath also becomes a part of his Blade when it goes Shikai. It might be a special case for his only.)
Q2. Why did Old Man Zangetsu always kept Ichigo's zanpakuto in released state during the initial Bleach?
Ans. This is a question that I don't have a very clear answer about so, you can consider this as the biggest flaw of my theory. I think OMZ kept Ichigo's zanpakuto always in release state because of his feeling to protect Ichigo. When Ichigo 1st returned to be a shinigami after Byakuya broke his soul chain in the 1st arc, his 1st battle was against Urahara(even if it was part of his training). Seeing the power gap between him & Ichigo OMZ might have decided to keep Ichigo's zanpakuto in shikai state the entire time so that it can act as his 1st line of defense. I mean Ichigo & OMZ both knew they will be facing captain level opponents in Soul Society. But neither of them knew how strong Urahara is and that he was also a Captain. So, it possible for OMZ to deduce that if Urahara is so strong then the Captains would be stronger. Thus, it would be a precaution taken by OMZ to ensure Ichigo's safety...
Q3. How did Ichigo gain his quincy powers back?
Ans. I can't provide the exact line but I think it was stated in CFYOW novels*(not as a meme)* that after Yhwach died the powers he absorbed started returning to their original holders with time. So, it might be the case for Ichigo too, where his Quincy powers returned to him with time after the battle. If anyone can point out the exact line it would be great of you. I think it was from the part where Liltotto. Bambietta & Giselle were moving around in Hueco Mundo.
This is all I needed to say. If you have any questions or want to point out any flaws in my theory, reveal any extra information that I missed, feel free to do so. You can also tell your own ideas in comments, I am excited to know what others think about this. Also I am pretty sure this topic might have been talked about a lot previously, so if this irritates you then my bad, I apologize. Thanks for reading & passing by the discussion...