Bleach's "Thousand Year Blood War" arc has finally been released after a decade of anticipation. The Soul Society is in ruins thanks to a handful of soldiers under Yhwach's command in the TYBW arc, which is the most intense the series has ever been. The King of all Quincies has returned after a thousand years, and he has a deep hatred for Soul Reapers. He will use any means necessary to achieve his goal of destroying all worlds. With the Gotei 13 suffering devastating casualties and Seireitei destroyed, all that remains is for Ichigo to finally recognise his true powers and launch a counterattack.
What is surprising is that the Soul Reapers are completely helpless against an army of Quincies, who are thought to be the weaker of the two races. Despite having a numerical disadvantage, Gotei 13 easily defeated the Quincies over a millennium ago. The fact that Soul Reapers are unable to inflict significant damage on the Quincies during the Quincy Invasion suggests that there is more to it than meets the eye. Apart from being strong, the Quincies' success can be attributed to a variety of factors, including having enough information against the enemies, stealing the Bankai, and keeping their motives hidden until the very last moment.
What Happened a Thousand Years Ago During Bleach's Quincy Invasion?
Unlike in the present day, the Gotei 13 from a thousand years ago wasn't considered a well-established organization. Now, there are 13 squads, each having one captain, one lieutenant and an unknown number of Soul Reapers. However, during the battle with the Quincy over a millennium ago, Genryusai Yamamoto simply gathered a group of excellent soldiers and formed a new organization to protect the Soul Society. The first-generation captains of the Gotei 13 are considered to be the strongest even to this day. Rather than a group of Soul Reapers, it would be more accurate to refer to them as a brutal mob of killers, thirsty for battle.
With the barest of efforts, they were able to put out the Quincies. When facing Yamamoto, Yhwach discovered that he had no way out. Even though the Soul Society doesn't take pride in having eradicated Quincies years ago, what they managed to accomplish is undeniably a testament to their unmatched strength. When the Quincy seemed to have vanished over the centuries, Yamamoto established the Gotei 13 as a legitimate organisation, and all the squads underwent significant changes, mellowing out in the ensuing peace.
The Soul Reapers of Today Are Significantly Weaker Than Their Forefathers
Just comparing the strengths of Yamamoto and current Head Captain Shunsui Kyoraku is enough to justify the statement that the strength of the Gotei 13 has diminished with every generation. Although Kyoraku is extremely strong, his powers can never reach Yamamoto's level. Similarly, Byakuya, Ukitake, Toshiro and others are all extremely talented Soul Reapers, but the first-generation captains were leagues apart from them. During the massacre, the Quincies found themselves unable to counterattack those killing machines. However, in the present, they are able to easily overwhelm the Gotei 13 with the same power. This goes to show that it is not that Quincies are invincible, but rather that the opponents they face prove to be weaker in comparison.
The Soul Reapers Pay a Heavy Price for the Lack of Information
The Quincies come fully prepared with enough information on high-ranking Soul Reapers. During the invasion, Byakuya and Renji face off against As Nodt and Mask De Masculine. However, Mask simply throws Renji off the scene as the latter is about to activate his Bankai. As Nodt calls Mask an idiot for losing a perfect chance to steal Renji's Bankai and mentions something about Yhwach's "Daten." As it turns out, Mask is the only one who doesn't pay attention to the information provided to them beforehand, but all other Sternritter are aware of the strengths and weaknesses of the Soul Reapers. Daten is a German word for "Data," which is collected by the Wandenreich and distributed to all Yhwach's soldiers.
On the other hand, Byakuya, despite belonging to a noble lineage of Soul Reapers, is unaware of a simple ability called "Blut Vene." He is genuinely surprised to see As Nodt efficiently blocking his attacks using this technique. However, it is unknown why the Gotei 13 has no information on Quincies despite having annihilated them over thousand years ago. During that time, it is highly unlikely that not a single Quincy used this ability. This goes to show how under-informed the Soul Reapers are about their enemies. One side has basically every piece of intel about their enemy, while the other is simply shooting in the dark. Given these conditions, it only makes sense for the Soul Reapers to lose so terribly.
The Layers of Mind Games Involved in Stealing the Bankai
The layers of mind games associated with stealing a Bankai are astounding. First, the Wandenreich announce war upon the Soul Society by killing the right-hand man of the head captain. They also give a five-day warning beforehand despite being confident of their victory. As he draws his last breath, Sasakibe makes sure to inform Yamamoto that the enemy can "seal" their Bankai. However, Sasakibe never finds out that the enemy can steal the Bankai for themselves -- he simply doesn't live long enough to find this out. The intel is, of course, passed down to the captains. During the invasion, a lot of captains use their Bankai against the enemy despite the risk. They make a gamble and try to turn the situation around, only to be defeated by their own ability.
Bankai is the ultimate form of a Zanpakuto that increases the chance of victory by five to 10 times, which goes to show how precious each captain's Bankai is. The confusion created in the initial episodes leads them to doubt their decision of using Bankai, wasting a lot of time in the process. It is highly likely that the Quincies purposely twist the situation in their favor by letting the Soul Reapers misunderstand the Bankai-stealing ability. Had they known that they can steal the Bankai instead of only sealing it, they never would have used it. Furthermore, the Quincies successfully bring down the morale of the Soul Reapers by stealing the only ability that stands a chance against them. As for the other captains that don't use their Bankai, they're likewise unable to gain the upper hand without their strongest ability to aid them.
