User blog comment:Xilinoc/Ch. 575 - THE KILLERS HIGH/@comment-24153155-20140404002617/@comment-5693502-20140405211648

Tanking a sword so you can get a clean hit ? That's not reflexes.

I can partially accept that. Yes, he's not the most intelligent character (they're reserved for your Mayuris, Uraharas and Aizens), but he is far from stupid. His extreme Blood Knight tendencies just vastly overshadows his intellect, and I mean vastly overshadows it. If you took away his extreme battle-lust (and only his extreme battle-lust) I'm almost sure people wouldn't be questioning his seeming lack of intelligence. Also his apparent brain power has not changed since his first appearance either; i.e. he's had those neurons all along. So underestimate his intelligence at your own peril.

Not to mention, if Yachiru hadn't been in danger he wouldn't have bothered to deduce Gremmy's powers at all.