Board Thread:Improvements and Issues/@comment-15519592-20130817040010/@comment-15519592-20130817050011

Okay, just re-read it. Volume 47 for those looking for the area in question. There is no mention of Aizen decreasing his power at all throughout the whole volume (the events take place over several chapters). In fact, he mentioned he's surprised she is still alive being so close to him. Both Keigo and Don Kannonji didn't feel a thing, and I would argue that Don, as much of a goof ball as he is, has more spiritual awareness, and definitely more powers, than Tatsuki. Poor boy would have died if Rangiku hadn't stopped him from touching Aizen.

However, and the part that you are probably thinking about, several chapters over and near the end of the volume, Keigo can suddenly sense Aizen as well when he couldn't before. It should be noted that ONLY Keigo seems to pick this ability up, the rest do not, not even Don nor Afro-san. At this point Aizen could have lowered his power so he could play cat and mouse with them out of amusement (Aizen: "Do you think you were found? I just stopped pretending to look for you"), but he doesn't mention doing so, meaning it's pure speculation.

Aizen did mention killing Tatsuki when he first found them would work towards his goals, as Ichigo should be coming with a new power and her death will help him awaken it further before she is 'rescued' by Don and Rangiku. Seeing as how Aizen simply walks after them the entire time instead of blasting them with Kido, which would easily kill them without disintegrating them, I get the impression he doesn't care about corpses. Of course, I also get the idea he is playing with them, but it does seem as if he is trying to kill them with nothing more than his presence, which would disintegrate them, which would make lowering his power during the initial meeting pointless.