When Yhwach began his invasion of Soul Society, aside from the raw power that scared even the most powerful Captains of the Gotei 13, the Sternritter also demonstrated a new and horrifying ability. Namely, using their Medallions, the Sternritter were able to steal the Bankai of the Gotei 13 Captains and use them against them. This is how Captains Byakuya Kuchiki, Sajin Komamura, Toshiro Hitsugaya, and Soifon lost their Bankai and were almost killed by them. So, to give them back their Bankai, Kisuke Urahara, the smartest character in the series, went to work and ultimately discovered a way to give the Captains back their Bankai and also to stop the Sternritter from stealing them again. In this article, we will explain what happened and how Urahara figured all of that out.
While doing research in Hueco Mundo, Urahara discovered the true reason why the Sternritter hated the Hollows. Namely, it wasn’t just pure animosity. The Hollows were actually the antipode to the Quincy, just like the Quincy were the antipodes of the Shinigami. The Hollow’s Reiatsu was actually toxic to the Quincy, and that is why they completely eliminated them. Realizing this, Urahara used Hollow Reiatsu to create the Shin’eiyaku pills, which would temporarily Hollowfy a Shinigami, their Bankai included, and thus make them unusable to the Sternritter; they could not steal them or use them because the toxic Hollow Reiatsu would kill them ultimately.
The rest of this article will focus on the Shin’eiyaku pills invented by Urahara between the first and second invasion of Soul Society by the Sternritter. We will tell you what these special pills are, how they work, and how Urahara discovered what he needed to do to return the Bankai to the Captains and stop the Sternritter from stealing them again. This article will contain many spoilers, so be careful how you approach it.
Discovering that the Hollows are toxic for Quincy was a key point that Urahara used to create the Shin’eiyaku pills
Going back to the beginning of the Thousand-Year Blood War saga, in which Yhwach and his Sternritter invaded the Soul Society, we have to remember that the whole saga actually started with the Arrancar Asguiaro Ebern, who was actually loyal to the Quincy, arrived in Ichigo’s room and starting a fight with the young boy.
Although Ebern was an Arrancar, he was, as we’ve said, actually in service of Yhwach’s Quincy Army, which is why he had been given some tools and powers that made him look more like a Quincy, despite actually being a Hollow. This is an intriguing fact, but more on that later. Ebern was no match for Ichigo, but it turns out he had a vile plan – he wanted Ichigo to activate his Bankai so he could, seemingly, steal it.
This was later confirmed to be true when the Sternritter invaded the Seireitei, stealing several Bankai, including Sasakibe’s (stolen earlier by Driscoll Berci, the Sternritter “O” – “The Overkill”), Komamura’s (stolen by Bambietta Basterbine, the Sternritter “E” – “The Explosion”), Soifon’s (stolen by BG9, the Sternritter “K”), Toshiro’s (stolen by Cang Du, the Sternritter “I” – “The Iron”) and Byakuya’s (stolen by Äs Nödt, the Sternritter “F” – “The Fear”). But, while the Sternritter in the Seireitei were successful in their endeavors, Ebern had no luck with Ichigo because Quincy powers could not be used against a Quincy, as was revealed later.
The Sternritter used their Medallions to steal the Bankai, and while it was initially thought that they were only sealing away the Bankai, they were shocked to find out that the Bankai was actually stolen and could be used against them. This, on the other hand, hindered the Sternritter from using their Quincy: Vollständig abilities. The other Captains were informed of this, and they did not activate their Bankai out of fear.
Now, the first invasion stopped at one point, and the Sternritter retreated until Yhwach ordered the second invasion. After Bazz-B almost killed Toshiro, Cang Du appeared and revealed that Yhwach ordered the Sternritter to kill those Captains whose Bankai they had stolen.
This is how we saw a repeat of four earlier battles. But there was a catch. Namely, as the Captains fought, Kisuke Urahara arrived from Hueco Mundo in Mayuri’s lab and presented him with small black pills he called the Shin’eiyaku. He then informed all the members of the Gotei 13 of his discovery, as the pills, when touched, would return the Banaki to their respective Captains and would stop the Sternritter from stealing them again.
But, how did Urahara do it, and how did he discover this? The Shin’eiyaku is a very interesting invention. Namely, after physical consumption, the Shin’eiyaku causes the user of a Bankai to temporarily Hollowfy, which is why it effectively acted as a form of poison for the Quincy.
Urahara used his knowledge of the Quincy and the fact that they could not absorb the Reiatsu of Hollows without having their Souls destroyed in the process to come up with this interesting little pill.
As we know, Urahara was in Hueco Mundo during the original fight. He went there with Icihgo and the others to save Hueco Mundo from Quincy, led by Quilge Opie. After Grimmjow helped them kill Opie, Urahara remained in Hueco Mundo and continued his research on the Quincy. There, he discovered the real reason why Quincy exterminated the Hollows, as he explained to Mayury. Namely, it was initially thought that it was simply hatred, as the pure Quincy detested the impure Hollows, but it was much more than that.
Namely, as it turned out, the Hollow Reiatsu was actually toxic to Quincy. Just like the Quincy were the polar opposite of the Shinigami, the Hollows were the polar opposite of the Quincy, and their Reiatsu was poisonous to them. This is why they could not absorb it without being killed (stronger ones could do it, but not for long), and that is why they simply eliminated the Hollows.
Of course, Yhwach realized that having allies among the Hollows was useful, so he allowed some Hollows to join his army, but this was a practical move more than anything else.
So, using these new discoveries and Grimmjow’s assistance, Urahara used Hollow Reiatsu, and his knowledge of the Hollowfication process allowed him to create the Shin’eiyaku pills. As we’ve said, the pills would infuse the Shinigami with Hollow Reiatsu and would temporarily Hollowfy them.
This would, in turn, make stealing their Bankai impossible, as stealing them would kill the Sternritter, as the Bankai was now toxic to them. As for those who already had the Captains’ Bankai, since the Bankai is tied to the Shinigami in more ways than one, the stolen Bankai also got Hollowfied, and the Sterntitter using them began to bleed and suffered the consequences of being poisoned with Hollow Reiatsu. This is why they had to return the Bankai immediately, or they would have died.
This was a genius move on Urahara’s side, and Kubo actually found a great way to return the Bankai and expand the lore, and we have now presented the whole story to you here.