The strongest castles were often breached from within.
So when striking at an enemy, the most effective method was always to amplify their internal contradictions and create chaos, opposition, and conflict.
One reason Aizen had failed in the original story was because he had pushed himself too hard toward destruction. Another was that he had failed to make good use of the severe class divide within the Soul Society.
There was no need to look any further than the ratio of nobles to commoners among the Gotei 13's Deaths to understand just how sharp the conflict hidden beneath the peaceful surface was.
Saying they were sitting atop a powder keg was no exaggeration.
All it would take now was a little incitement to trigger a whole chain reaction.
You must know that the souls of the Soul Society were essentially people too, and humanity's greatest trait was its endless dissatisfaction.
In the past, commoners who entered the Gotei 13 had no right to choose. They could only muddle through within the sole existing system, accumulating seniority. Even if they were lucky enough to become captains, that was as far as they could go. They simply could not touch the core of power monopolized by the nobles—the Central 46 Chambers.
But now, they had a new option.
They could side with Aizen, overthrow the Seireitei's current order outright, kill the Spirit King, and then reshape the Three Realms.
Of course, before that, Allen still had one more thing to do: kill Genryusai Shigekuni Yamamoto.
Otherwise, with that powerful and ruthless Captain-Commander keeping everything in check, those below might not dare cause trouble.
The conflicts between the division captains in particular would undoubtedly be easily resolved by him.
After all, as the founder of the Gotei 13, the remaining captains were either