User blog comment:Salubri/Aizen, Yamamoto and Wonderweiss/@comment-452405-20100227060738

I guess by using a technique that could take out the old man himself would make sure Aizen was killed too, either that or Kubo wants the manga to look more flashy. Personally from an artist's perspective simply slashing Aizen would be a boring end to the guy who has completely eliminated most of the captains and Vizard. A technique this big also signifies the extent the old man will go to just to make sure Aizen doesn't come back.