User blog comment:Skitzo1/Ichigo is pretty Ignorant?/@comment-30811407-20130803043410

While I agree, in Ichigo's defense, he had no reason to trust the real Zangetsu so far, who turns out to be quite the sadistic Zanpakuto.

He first met his Quincy powers who claimed to be his zanpakuto, so he had a skewed view from the get-go. Still, Ichigo should have known something was up.