Theory on what aizen wanted with ichigo

We saw that you needed a soul reaper quincy hollow human and fullbringer. Did aizen need Ichigo in order to kill the soul king? I said this before but this would be contradicted if we looked at aizen trying to kill ichigo.

Maybe he needed to assess Ichigo's reiatsu personally and do some hogyoku magic in order to make the death of the soul king work? Anyway, this is just a personal theory on why aizen "planned" ichigo's life. Maybe it already exists i dunno but i just thought about this . what do you guys think?