User blog comment:Fangowango/Inconsistencies/@comment-3996324-20130315114307

1. Aizen told it go there, he wanted to see Ichigo release his power.

2. well, the command of coming to find Rukia was given(indirectly) by Aizen. Since he controlled the central area where they give out important orders, it was easy for him to send members there "when" he wanted to.

3. I'm guessing friendly relations were established at some point between them, so Rukia reporting him wouldn't be a problem.

4. Maybe he's the last of the "pure" Quincys. As in, not related to normal humans.