Ulquiorra didn't often interact with his siblings unless ordered to. He found that he worked best alone. There was no need to waste manpower when he could accomplish alone what might take many of his siblings to do. It wasn't so much a measure of arrogance, but practicality.

The fact that he allowed Yammy to tag along was an anomaly. It didn't fit in with his loner tendencies or his philosophy. Some had even shaken their head, not surprised in the least, when they heard it hadn't been any of the opponents they had faced that day on the mortal world, but Ulquiorra, himself, who had been the one to take Yammy out.

Yammy grimaced and bore it. He had never expected Ulquiorra to have the same gentle kindness of the leader they both shared. It was the ruthless efficiency he looked for in the arrancar leader. It was the spot-on ability to tell him what to do at a moment's notice that made him comfortable to submit to. It was the fact that Yammy could crush his head without a second thought and Ulquiorra still felt at ease in his seat of arrogance that sealed things for him.

And, more than anything else, it was the fact that once they finished their reports and Ulquiorra ordered him to see the medical arrancar, it didn't take Ulquiorra long to return to the room with the remains of Yammy's arm, carrying it with ease despite his smaller size. His dull green eyes flickered over Yammy's frame, "A one-armed arrancar would be useless. I'd like to think you still have some measure of worth, Yammy."