"Remember that a sword held by someone who is about to die… will never be able to protect anything."

"You know why big brothers are born first? To protect the little ones that come after them."

"[to Chad and Orihime] Your transformation is not a disease. You were just given the key to the door in front of you. There's no need to know the cause. No need for sorrow or sadness. What comes next is up to you. You can use your keys to open the door...or lock it tight. And if you do choose to open it... You can still decide not to pass through."

"Oops. They found us."

"Can't you tell, Aizen? You no longer have a place to run away to."

"What would you have me say? "Don't worry, I'm sure he's still alive."? Ridiculous. I am not here to comfort you. I don't understand why are you so fixated on life and death? At any rate, your friends will soon be annihilated. So what if that's one step closer? They should have seen this coming from the start. If they couldn't see it coming, the fault lies in their own foolishness. Laughing them off as a group of idiots would be sufficient. Why can't you do that? If it were me, and my friends entered Hueco Mundo without first gauging their strength, I'd be infuriated by their stupidity."

"[to Szayel Aporro Grantz] Immaculate being... Was it? In this secular existence, perfection is an illusion, regardless of those who utter the contrary. This is the reality. Common man seeks it out, they strive to achieve it, as if it were some tangible thing... But... The fact of the matter is, perfection is a hollow shell. It is devoid of any substance. I spit on perfection. Perfection, after all, implies you've reached the summit. No trial and error, no ability to conceptualize. An omniscient being would have no need for such superfluous things... Am I making myself clear? For people who dabble in the sciences, such as ourselves, perfection would make us obsolete. Many magnificent things have been, and will continue to come into existence... And yet every last one of them will fall short of perfection's finish. Our function as men of science relies on their many shortcomings. Then, and only then, can we apply the fruits of our labor. To put it simply... As soon as you began spouting that nonsense about being an immaculate being... your fate was sealed. How dare you call yourself a man of science?"