Aizen approaches you with a confident smile and gazes at you with an unshakable confidence, poised for the impending clash “I don’t care what spell or power you have. I will show you their futility before me” He taunted, his voice dripping with arrogance and condescension as he gracefully unsheathes his gleaming sword

You prepare to make the first move, but Aizen, ever the one to take notice and advantage of the slightest weakness in someone, calmly makes his move before you even had a chance to register anything.

“Too slow” Aizen utters calmly.

In the blink of an eye, Aizen’s incredible perceptiveness and intellect found your unguarded spot and shunpo in front of you, driving his zanpakutō through your chest, blood spraying like a fountain.

SLASHHHH

A habit of his, it seems like he planned out this fight well in-advanced. Despite his arrogance, Aizen was highly cautious going into battle even placing protection spells on himself to cover his worst blind spots, like the pre-placed barrier spell (Millón Escudo). In the rare event that an opposing power catches Aizen off-guard, he remains calmly observant to devise an impromptu counter, as seen when he fell victim to Shinji's Sakanade, which inverted his perception; after being struck once, Aizen re-adjusted his brain's sensory input and reflexes to fight completely backwards, a feat that astonished Shinji. In keeping with his manipulative nature, Aizen often relies on verbal warfare, using taunts to goad adversaries into letting their guard down and, ideally, into taking fatal missteps during combat.

Knowing his taunts worked, he smiled coldly.

“You’ve left yourself… wide open” He says coldly and calculating, as he brutally cuts you down in half when you rushed him in anger

On the off-chance that Aizen will come up against powers or intelligence greater than him, Aizen is intelligent enough to prepare countermeasures for stronger/more intelligent opponents to avoid facing them directly. Such as with Yamamoto. Aizen believes that Yamamoto is the only captain whose powers are a rival, if not greater to his, and as such, Aizen does not take any chances and simply creates a plan to deal with his opponents superior powers. Aizen's cunning is so advanced he can overcome overwhelming odds with his planning.

Aizen’s theme song “Stand Up Be Strong (Pt.1)” plays in the background while your crumpling body’s on the floor.

“A group offensive. Distractions. Sneak attacks. Decoys. To battle me, you’ll need to use all of those battle strategies and more. You’re chance of capturing me is very slim” He lectures condescendingly with unnerving calmness, but he’s actually right.

Aizen would never attempt to attack twice without first thoroughly thinking it through. He’s thought about everything

NARRATOR: “Now you see… others don’t fear Sosuke Aizen just because he can use his Kyoka Suigetsu to destroy them. Yes, Kyoka Suigetsu’s power is terrifying. But fearing it alone wouldn’t have been enough to subjugate all those who would rather die than obey. There was only one reason why those powerful Espada were able to function as a group, in spite of their widely different personalities and uniquely individual motives…. It’s because Aizen is strength itself. His power, speed and precision all exceed that of a normal Soul Reaper. He has no equal. You can attempt to safeguard against his Kyoka Suigetsu all you want, but you could never prepare enough. Even if you put your heads together, he will outthink you. Take all the precautions you like against unfortunate happenings like the sky falling… or the Earth splitting… But I can assure you, there’s really no use in trying. Create all the elaborate plans you want. But his superior powers will undo any of your schemes.”

He’s already behind you again… but how?? He’s already outthought you… already outsped you… already outhaxed you… already outclassed you… You’ve fallen into his trap instead

“I told you didn’t? That I would show you” Aizen smirks, unfazed by everything