I'm still in tears over Ulquiorra's last name.
Ulquiorra liked order and efficiency.
He liked to kill his prey fast, severing their soul from their bodies in a singular motion. Toying with them was merely a waste of time.
He like the hierarchy Aizen-sama had created among the Arrancar, which kept his weaker siblings in their places and in awe of the Espada.
In a sense, he also liked Yammy. The large hollow was a simpleton, a combination of oversized muscles and an underdeveloped brain. His actions were easy to predict and he was a loyal soldier.
What he didn't like, was Grimmjow Jaggerjack, the Sexto Espada. Grimmjow was an enigma—No, rather an annoyance, his moods swinging unpredictably, often going through several changes within a single conversation. Ulquiorra didn't like the fact he could never predict what obscene act the larger Arrancar was going to pull next, he didn't like the fact that everywhere he went, he would bring noise and chaos and – if they had been human – migraines, and he especially didn't like the leering eyes that never stopped mocking him, undermining his authority from across the meeting table.
Ulquiorra liked efficiency, and Grimmjow was anything but. Losing five of the Arrancar was despicable enough, but on a trip to the human world, of all places. Grimmjow held meetings up and disobeyed Aizen-sama on a frequent basis, which only meant Aizen-sama had to take time off whatever he was doing to punish trash like him. He was rough, a simpleton, every sentence he spewed crudely laced with expletives, using too many extra words to express a singular thought. Grimmjow was insolent, often resorting to childish actions like eye-rolling and melodramatic sighs and raucous laughter in the middle of their meetings, usually interrupting someone's report. Ulquiorra's warning Reiatsu would only warrant a cocky smirk from the larger Espada.
The only thing that Grimmjow had going for him was his brute strength, but even that couldn't protect him against Aizen-sama.
When Tousen-sama had lobbed off Grimmjow's arm, Ulquiorra had allowed himself a small (very small) smile and went to fetch Grimmjow's replacement from the lower Arrancars' quarters without a second thought. When it came time for the induction ceremony, he was naturally unbothered when Aizen-sama tattooed the number six onto Luppi's body, and he could barely find it in himself to care when Luppi was introduced to the rest of the Espada.
However, he couldn't help but feel a little unsettled when the meeting the next day when the meeting went without an interruption from the seat across of him.
Ulquiorra didn't like it.