This is a suprising news. Shinji was the capation of the 5th squad. And he left Soul Society 110 years ago. When he was the captain, Aizen was only the vice captain of the 5th squad. Now the question is how he became a Vizard from a Shinigami.

Now the story become more and more interesting. All the captain level Shinigami, Vizards, Arrancars, and the three previous Shinigami captain have gathered in Karakura. A big battle will begin.

However, it seems that Aizen is the final boss in this manga. I think if Ichigo can control his inner hollow and fully master his Bankai, he will reach the level of Aizen soon. But now the next enemy for him is the 4th Espada, Ulquiorra. I wish Ulquiorra has a nice release form.