why use Mugetsu??

[Jaengusu]

I think it was to seal Aizen or such. I remember Urahara saying that Ichigo and the rest helped it make it easier for him to seal him.

[Typhon]

The problem was that Aizen regenerated too fast. Any damage he dealt with his normal attacks would be almost instantly healed and he would have eventually run out of steam.

[uncle sam]

It was probably exhausting being in the combined state...a drawn out battle would be to ichigos disadvantages..he used mugetsu in an attemp to finish aizen off instantly..hogyokou saved aizen but then stopped feeding him power,so he was effected by kido

aizen is so awesome!i hope he makes a comeback

[origin29]

probs because it was dope as all hell.