(Treachery - Shiro Sagisu)

https://youtu.be/0kYq-E8BJgU

Adam: The Soul Society was in chaos. One of its leading Shinigami was set to be executed under suspicious circumstances. A band of humans from the living world had invaded to save her, and Sōsuke Aizen, captain of the Fifth Division of the Gotei 13, was dead. Murdered.

Randy: What dastardly mastermind could've been behind all this?! He'd have to be a galaxy-brained 5D chessmaster!

Adam: The man responsible was, in fact... Sōsuke Aizen. Little is known about the man's past, only that he isn't a mortal man, but a Soul Reaper. These Shinigami are spiritual beings who ferry lost souls to the afterlife, and purify those who have turned evil in the living world.

Randy: They're badass anime wizard Grim Reaper swordsmen, though Aizen himself was hardly that cool. I mean, just look at those glasses. Dork.

Adam: But this Clark Kent was harboring a secret. Aizen had spent years attempting to develop the means to ultimate power, ruining the lives of many of his colleagues via his twisted experiments. Aizen's plotting finally came to fruition during the invasion of the Soul Society.

Sosuke Aizen

Expert strategist

Skilled swordsmanship

Reiryoku

Kyoka Suigetsu

Hogyoku

Invisibility

Hakuda

Reishi Manipulation

Shunpo

Incredible Reiatsu

Zanjutsu

Kidō

Millón Escudo

Bakudō #26: Kyokko

Hadō #63: Raikōhō

Bakudō #81: Dankū

Hadō #90: Kurohitsugi

Hadō #99: Goryūtenmetsu

First Fusion

Second Fusion

Third Fusion

Fourth Fusion

Final 

Fragor

Ultrafragor

Randy: Being a Shinigami, Aizen is invisible to any human eyes thanks to his his body being composed of a spiritual matter known as Reishi, though they still can be physically touched and can exert a powerful spiritual pressure called Reiatsu which can kill lesser beings than him. He also utilizes spiritual energy known as Reiryoku, which he can use spells called Kido for a bunch of attacks. Like Kurohitsugi, a black coffin which distorts space-time and tears its victims apart. Or Goryutenmetsu, which are basically giant purple energy dragons. And Aizen is very smart, always planning ten steps ahead of his opponents.

Adam: But let's talk about his two iconic and absurdly powerful weapons: Kyoka Suigetsu and the Hogyoku. Kyoka Suigetsu is Aizen's Zanpakuto which are essentially sentient weapons and takes complete control over all of a target's senses the instance they laid their eyes on it. This ability called Complete Hyponsis create nearly perfect illusions that Aizen can create at will, leaving their targets sitting ducks for Aizen to take out. Then there's the Hogyoku, a powerful reality-warping device that grants the user's wishes.

Randy: It also evolves the user to become even stronger while nullifying any weaknesses they had before and gives them insane regeneration.

Feats

Achieved the Ranks of Lieutenant and Captain of Gotei 13's 5th Division

Considered one of the smartest in the Soul Society

His massive Spiritual Pressure can disintegrate beings that are not on his level

Created several Hollows and Arrancars before his defection

Mastered Hakuda to fight free-handed without his Zanpakutō

Invented the Hōgyoku and Caja Negación

Can successfully use Hado Number 90 Kurohitsugi without incantation

Survived Ichigo Kurosaki's Mugetsu, an attack that, when scaled generously, has a maximum destructive yield of 800,000,000 Megatons

Regenerated from having a giant hole blown through his chest by Gin's poison

Aided in Yhwach's defeat, nearly consumed by the Quincy's powers

Was stated to have retained his Spiritual Pressure from when he achieved his Final Fusion in his base form

His Zanpakuto can put Yhwach under hypnosis twice

Endured incineration from his own Reiatsu

Moves FTE to top tier Shinigami

Stopped a hadou from Tessai

Caught Ichigo's Bankai with his finger

One-shot a being immune to Reiatsu

Defeated the Gotei 13, the Visored, Urahara, Ichigo

Randy: Aizen proved to be one of the strongest beings in Bleach. He's bested the other Gotei 13 with ease, used Kyoka Suigetsu to trap the Visored for a hundred years without them even knowing and stopped Ichigo's Bankai with his finger, a feat so absurd Aizen it even the music was cut off. Yeah that's right, Aizen literally stopped a protagonist's theme song.

Adam: Thanks to the Hogyoku, Aizen has transcended beyond Shinigami and Hollow alike, the the point he's even capable of dethroning the Soul King himself, who had enough power to hold Earth, Soul Society and Heuco Mundo simultaneously at all times. Assuming they're all the same size, this puts Aizen's power at least 143.403 Zettatons of TNT.

Randy: And while teaming up with his former rival Ichigo, they overcame Yhwach, who usurped said Soul King and even put him under hypnosis twice with Kyoka Suigetsu.

Weakneses

Has a bad habit of explaining to his opponents how his Zanpakuto works

Is very quick to underestimate his opponents, especially "lowly humans"

Becomes less cautious, more arrogant and overconfident when granted power

Surpassed in power in his Final Fusion by Ichigo Kurosaki

Kyoka Suigetsu cannot work on the blind and will be impaired when used against someoone w

Overwhelming attacks may force Aizen to return to a previous Fusion

Attacks like Mugetsu might convince the Hōgyoku to reject Aizen, making him lose the abilities he gained from it

Despite becoming a Captain of the Gotei 13, Aizen has never displayed access to Bankai, likely indicating he doesn't have access to his, or his Zanpakuto flat-out can't achieve Bankai

Adam: Aizen is undoubtedly overpowered, but he still has his faults. Mostly notable his habit of underestimating those beneath him like humans and being arrogant. This led to Aizen having a breakdown when he can't understand why Ichigo was stronger than him and being caught off-guard by Yhwach when he deactivated Kyoka Suigetsu believing he was killed.

 Zanpakuto's Complete Hypnosis can also be deactivated if they touched the blade befor it was released, though its no longer an issue since Kyoka Suigetsu fused with Aizen. Even then his illusions aren't perfect since Unohana managed to detect flaws and Yamamoto was confident he could sense Aizen at close range through his Reiatsu despite Kyoka Suigetsu's ability to trick sensing abilities.

Adam: And should Aizen's will falter, the Hogyoku will reject Aizen as its master which led to his defeat by Ichigo's hand and sealed by Urahara. But no matter his flaws, Aizen is always planning, seeking to claim total power.

Aizen: From the beginning, no one has ever stood at the top. Neither you, nor me, nor the gods. But soon, that unattainable vacancy of the top will be filled. From now on..... I alone will stand at the top.