Sōsuke Aizen is, of course, known as the first major villain of Bleach and although Yhwach was far more menacing, he never actually became as famous and as notorious as Aizen. Now, Aizen was locked away after being defeated by Ichigo but he reappears later as an enemy of Yhwach, after declining his offer to serve him. Aizen would eventually joins forces with Ichigo against Yhwach and will help save Soul Society in the final battle of Bleach. In this article, we are going to explain why he did it.
Labeling him a “Special Threat”, Yhwach approached Aizen to serve under him as he crushes Soul Society. Aizen politely declined and even messed with Yhwach perception a bit. Later, he was freed by Yhwach who still declined to join him, instead helping Ichigo kill the Quincy Emperor. Why? Aizen was a proud Shinigami and a narcissist who did not want anyone to rule over “his” world, as well as him. It was out of selfish reasons, but Aizen’s help was truly immeasurable in this context.
The rest of this article is going to tell you two things. First of all, we are going to talk a bit about Aizen’s personality and the reasons that drove him to help Ichigo and not Yhwach, although he shared the same goals as the latter. After that, we are, of course, going to tell you how the fight went down, which is why you have to be careful because there are going to be many spoilers in this article.
Why did Aizen help Ichigo against Yhwach?
In order to fully understand Aizen’s reasons, we have to tell you a bit about his personality. Aizen actually has two sides to his personality. Aizen initially appeared to be a very friendly, well-respected Captain and was admired by many, especially his second-in-command, Momo Hinamori. Always polite and respectful, he won the popularity and trust of most members of Soul Society.
However, this was only a mask to disguise his very dangerous and cold-blooded nature. In truth, he cares little about his subordinates (both in the past and in the present) and is willing to use almost any of them as a tool in his own constructed game “a chess game”. According to his own statements, he is not bound by any moral concepts, as he sees them as an annoying limitation of his potential. For example, he would also kill or manipulate someone if he deems it necessary.
He loves long, complicated, and somewhat confusing speeches, most of which don’t really make sense until he explains his intentions, often using his subordinates as playthings for mere entertainment. Unlike most other Shinigami, who possess honor and kindness even when fighting an Espada or Arrancar, Aizen never shows compassion or pride, save for the final arc. He also rarely shows any sign of concern or remorse, and often has entire events planned well in advance.
When many of his subordinates, including Kaname Tōsen, fall in the battle of Fake Karakura Town, it becomes clear that they were just a means to an end for Aizen, as their deaths hardly bother him, in most cases he just looks the other way or dumps himself even of his “too weak” subordinates, saying they just aren’t strong enough to fight for him. However, when Aizen is on the verge of achieving his goal and possessing incredible powers, he seems to overestimate his power and has lost the habit of overthinking everything. Instead, he says no one can harm him now.
Aizen’s actions could best be described as a rampage. He had actually already done with his wish to just be like the others, and accordingly wanted to change the world. To do this, he had to overthrow the Soul King, who, according to Urahara, is the core of the spiritual world. Aizen probably didn’t care if he was stopped if someone had the power to do so, or if he made it. In both cases, it would have been the fulfillment of a wish.
However, Hougyouku gave him even more powerful powers, which made it impossible for him to recognize an equal as such. Also, he couldn’t comprehend how a human could be stronger than a Hollow, a Shinigami, or even anything surpassing those two. Still, his heart’s greatest desire to have someone in his league was fulfilled the moment Ichigo trounced him.
However, due to the power rush and blind trust in the Hogyouku, he didn’t realize that he was losing his powers but only understood that the Hogyouku decided that he no longer needed a zanpakuto. Aizen himself even explains the reason for his despair, saying to Shinji Hirako that every being needed someone stronger to trust. Since Aizen didn’t see that stronger person in anyone or had simply surpassed everyone, he also had no one to confide in to hold on to and he broke down psychologically.
Ultimately, Aizen was a narcissist but he did feel some personal pride as a Shinigami, considering himself to be far superior to anyone else. Namely, Aizen considered himself to be the most powerful character in the series. Although he was aware of the strengths that other characters had, he considered himself capable enough to overpower or outwit all of them; this is why he actually went for the Soul King, the deity of Kubo’s world. He ultimately failed because of said narcissism, but this is an important thing for understanding his final decisions.
Namely, when Yhwach approached him to join him as his underling, Aizen respectfully declined, knowing that Yhwach would not kill him that very moment. He calmly waited to be freed, as he had probably anticipated that Yhwach would do it eventually, and then, instead of a thank you to the Quincy Emperor, he helped Ichigo kill him. He was too prideful, both as Azien and as a Shinigami, to allow a Quincy to rule over him, but also over “his” world, as he still believed that he was the only one destined to rule over Soul Society. This is why he ultimately helped Ichigo and let us now see how the battle evolved.
How did Ichigo and Aizen defeat Yhwach?
During the Thousand-Year Blood War, Yhwach, knowing Aizen’s power, wanted to recruit the rogue Shinigami to his cause, but Aizen outwardly refused. Yhwach then set him free later on, but Aizen thanked him and then turned on him. Yhwach questioned such a move, but Aizen simply explained that he did not want anyone controlling him, not even Yhwach.
While Aizen and Yhwach were talking, Renji and Ichigo attacked the Quincy Emperor and a fight between them ensued. Now, this is where Aizen’s Kyōka Suigetsu really came into the spotlight, as it not only helped weaken Yhwach, even if by little, but it also gave Ichigo the necessary opening to actually defeat and kill Yhwach.
Following Yhwach’s initial assault on Ichigo, Aizen engages in a Bankai attack while posing as Renji, but Yhwach breaks off his left arm and simply decides to destroy Aizen personally. Aizen then uses Hadō 99, Goryūtenmetsu, an extremely powerful spell, which shatters the earth around them and, above all of them, creates a giant dragon made out of energy that charges forward, before returning to his original form while keeping his Zanpakutō intact.
Yhwach mocks him for it and Aizen then appears to protect Renji from him. Regardless of everything, Yhwach simply remarks that Aizen’s blade is broken before launching him backward with an energy blast. Yhwach concludes, victoriously, that even the powerful Kyōka Suigetsu is useless compared to his enormous power. He then proceeds to stop his sword as Aizen, posing as Ichigo, arrives behind him with Tensa Zangetsu.
Aizen then compliments Ichigo for picking up on his use of illusions so quickly and describes how he used Kōyka Suigetsu’s strength to defeat The Almighty before commenting that Ichigo was the last step in his plan because he was unaffected by his illusions. While they’re talking, Yhwach collapses into a pool of darkness. Aizen admits that he never imagined that keeping Ichigo away from his Shikai would be so advantageous to him, and is shocked when the pool of darkness surrounding Yhwach suddenly bursts and engulfs him. Ichigo would soon defeat Yhwach for good, and Aizen was imprisoned once again; ten years later, he finally felt the last traces of Yhwach’s Reiatsu disappear.
This battle was overall too short to give us a proper insight into the power balance between these two characters, but it was enough for us to see how cunning of a fighter Aizen was, even when facing Yhwach, who was thought to be invincible and who killed Yamamoto. Aizen definitely had something to say against Yhwach, but as the Quincy Emperor himself said, he was relatively immune to the powers of Aizen’s Shikai, which gives him the ultimate advantage in this fight. This is why we actually have Yhwach win this one, as, without Ichigo’s help, he would’ve been killed by Yhwach.
There is a chance that Aizen might have defeated Yhwach with his Bankai, but since we don’t know Aizen’s Bankai and what its powers are, we cannot attest to this; it remains only a possibility.