Bleach: Thousand-Year Blood War continues the main story by introducing Yhwach, the Quincy King.
He awakens a thousand years after his “death”. To gain his power, Yhwach uses a technique called “Auswählen”, which strips power from every Quincy in existence.
This technique took the lives of Ichigo and Uryu's mother, but not all of the Quincy died. For years, it seemed like this was an inconsistency in the story, but Tite Kubo finally revealed the reason behind it. In a Klub Outside fansite, Kubo answered a new question, shared on October 21, 2024.
The 689th question on the site is: “Regarding the investiture ceremony that takes place at the end of the series, Bambies and Buzzbee continue to use the sacred characters and there is no indication that their abilities have been taken away . Considering that they were of a relatively young generation, perhaps the older Quincy received the full investiture first, and the amount of power needed at that time.”
Author Kubo answers this question saying: “The necessary amount of power is taken from old and weak Quincy, in that order. In addition, Bazz-B and the girls are young, their abilities are also at the level altitude. Therefore, their protection against Auswählen is naturally high, resulting in them only being 'reduced' in strength”.
A popular Bleach fan account on Twitter/X shared this information:
“It's time we got an answer. I think my speculation about Uryus' wound taking Jugram's life while weakened finally makes sense.”
“This was so obvious to me when the manga first came out, but people kept saying Auswählen was inconsistent like it weakened old and weak Quincies like Robert or Uryu's mother, and weakened stronger younger ones like Masaki, who only died because of Grand Fisher.” another shared.
Another fan added: “Thanks to whoever asked this because I've always wondered why Auswählen seems inconsistent. This answer makes sense now.”
And why doesn't “Auswählen” affect Ichigo, Yuzu and Karin? That's because Ichigo is not an official Quincy. According to the Old Man, the Quincy power is only a small part of his power, Zangetsu (Shinigami + Hollow) is Ichigo's greatest power.
For Yuzu and Karin, the explanation is quite similar. They are not complete Quincy, there is also another power within them, and so Auswählen cannot influence them.
We don't know exactly what Yuzu and Karin received from their parents. We know Ichigo received White sealed inside Masaki, and that's how his Hollow and Shinigami powers became one and the same. But if we go by what we know, Karin and Yuzu should at least have Shinigami and Quincy powers, but no Hollow powers.