User blog comment:Xilinoc/Ch. 540 - The Sword Five/@comment-5028341-20130605152416/@comment-7488132-20130605153543

Nah... because Aizen was not expecting for "White" to attack Masaki, this is what intrigued Aizen, that "White" chose her instead of Isshin as his opposite.. For Aizen, Ichigo was an experiment all along...