Board Thread:Questions and Answers/@comment-10797017-20130624101208/@comment-5551986-20130714175918

Stefan (Shikai - "Rust & Shatter") wrote: N-e-ls wrote: Urahara is a master of Kidō. During his fight against Aizen, he could've used Hadō #125 instead of going through the trouble of inventing 2 ad hoc Kidōs beforehand.

Then I suppose Kisuke also could've used Hadô 97, 98, or 99, all which are more powerful than the level 91 he utilized, so that reasoning is flawed at best. I doubt he would have had a reason to use the higher ones, maybe he doesn't know them, maybe he thought it would take to long. But more importantly I think hado 96+ require some sort of sacrifice. If number 96 was that powerful, and it needed an arm. I would assume the higher kido would need a greater sacrifice.