Why Was Urahara Experimenting with Hollowfication?
The original raw text reads as follows:
「虚化」というのは… 魂魄の強化を研究する上で到達した"解"の一つです… "Hollowfication" is one of the "answers" I reached in my research on strengthening the soul… その過程で 僕は虚と死神の境界を瞬時に破壊創造する物質を作クました… In the process, I created a substance that can instantly destroy and create the boundary between Hollows and Shinigami…
本来は死神の魂魄な強化する為のものでした しかしモの制御は我々の技術力の範疇を超えていた Originally, it was meant to strengthen the soul of a Shinigami. However, its control was beyond the scope of our technological capabilities.
I draw your attention to the bold text. The direction of Urahara Kisuke's research at the time was strengthening the konpaku of shinigami. Hollowfication was one avenue of pursuit, but it was never the goal of his research.
What's interesting to me about this in particular is the emphasis on strengthening the konpaku. The purpose of the research was not to diversify modes of attack, or create overwhelming force, but to make the konpaku itself sturdier.
Why would he want to do that? Well... you may or may not have noticed, but Urahara Kisuke is not the tankiest guy. Nor is he a melee fighter. He's a ranged fighter at best whose most effective weapon is guile.
He could stop skipping leg day, arm day, and everything else day at the gym and actually train, as we see Soi Fon doing one-armed handstands on mountaintops, but he doesn't.
(While Reigai!Kisuke is anime-only, he does offer a legitimate and pithy observation. Read the manga closely and you will not see him using Hakuda—this is an anime-only invention. In addition, his Zanjutsu is... lacking. He's good at startling an opponent with his aggression, and that's about the extent of it.)
By the way, why does Soi Fon train? Because Shunkō requires it. It's a discipline that involves complete self-mastery as it requires channeling Kidō through one's konpaku with enormous self-knowledge and skill. To do so, one must train the body to handle the Kidō, control the Kidō, control the body, and supply the reiatsu. Few have trained and honed their technique to the extent that they can use it at all without burning themselves up in the process, much less master it.
And Yoruichi can do it best.
It is at this point that I will remind you that Urahara Kisuke has "borrowed" some of his techniques—mod souls from Kirio and healing springs from Tenjiro, to name a few—and cheated his way to others, in particular bankai. This is not a man who will derive things from first principles and devote decades to tedious training when a shortcut will do.
So it seems reasonable that the particular konpaku he was most interested in strengthening would be his own... as a shortcut to the one special technique still out of his reach: Shunkō.
