"You offer nothing of value, Arrancar...you request will be denied as such just as Karyu-san said, this Hiroko you speak of is our enemy as well as the rest of your race..." he says firmly then folding his arms with a stoic expression, "That being said, you are guilty of the crime of the consumption of human souls in your previous Hollow state, disruption and posing a threat to the balance us shinigami are trying to uphold, and any other crimes you've committed as an Arrancar. Because on of my swords is inside of you, you are unable to use your spiritual power in anyway...if I place at least two or three more inside of you, it is very likely that your spiritual body will crumble due to spiritual 'circuits' being fried and unable to keep your body together. My patience is already very low for your kind, take too long and I will do just that..." he threatens her, not changing his expression at all.
So she knew Hiroko too, that meant there was a good chance that she knew Valentino Rosa and Isabella Mora as well. That being said, she was an associate of them so that made her a designated target of him as well. He had five of his shikai's swords left as well as Chi's zanpakuto and he wasn't going to hesitate to use them. Ash had better start asking his questions and this Arrancar had better give her answers as quick as she could. To be honest, Aiku felt sick in his stomach for doing this interrogation as well as using such methods with a woman...hell, she wasn't even holding her weapon in her hands. But the fact of the matter was that Aiku was bitter and he needed to get this out of his system, she was a Hollow taking on a human appearance anyway so his feelings about this were only a natural reaction...it's what made these people even worse than the normal Hollows.