Shinigami Savant Quest #60

You are Kusajishi Riku, a shinigami and Captain of the Ninth Division of the Seireitei's Court Guard.

The inner world of your own soul is a desolate landscape, but at the same time it has always struck you as a surprisingly calming place despite its inhospitable appearance. The low hiss of gasses as they escape from the burning, blackened earth beneath your feet greets your ears, interrupted only by the crashing of distant waves on a rocky shore. A ceiling of stormy gray clouds stands motionless in the sky above, as if they were painted onto the inside of a dome by some masterful hand rather than having arisen due to some natural phenomenon. And the lone cherry tree where your zanpakuto spirits stand, eternally locked in luminous bloom, fills the still air with the faint but evocative scent of sakura.

Sometimes you wonder if anyone else's inner world is this weird by default.

“The first way of Ura Hadō, called “Sōgenbi”, is a dangerous technique in many ways,” your first zanpakuto Tenkotsuki explains, her nine golden tails swaying behind her idly, almost as if they were actually capable of boredom and restlessness. “To learn, to use, and in the existential sense. However such a technique is not without its uses... else it would never have been created in the first place.”

“I fear the time may soon come when you will need it.”

That sounds unusually ominous. “How do you mean, Tenkotsuki?”

“Before I sealed myself away from Muramasa,” she explains, recalling the moment when the rogue zanpakuto tried to forcibly “release” her from you and control her mind for his own ends, “I felt something that concerned me greatly. Something elusive, behind the chaotic and confused mass of his own energy and the hollow energy which currently sustains him.”
>1/?

Ah, so that's how a zanpakuto could remain active in such a state. With his wielder sealed rather than killed, all Muramasa would need to do is find an alternate method for resupplying his own reserves of reiatsu. With spiritual energy and a living wielder, of course he could survive long enough to pose a threat once more. But to feed on hollows for such a long time... his wielder must have been sealed well before you even joined the Onmitsukidō, maybe even before you died in the living world.

“He can't possibly be stable,” you conclude, your tone darkening at the realization of how dangerous Muramasa may still prove to be.

“Worse still,” Rosa continues, her echoing voice picking up where Tenkotsuki left off, “the vixen here told me hollows may not be all he's been eating.”

“I take it you're not talking McDonald's.”

“Though it would not surprise me to find one in Hueco Mundo, no,” Tenkotsuki sighs.

“Alright,” you frown, “so that's why you seem to think the time's right to learn it. But what's this about an “existential” danger?”

“Sōgenbi itself is the Saishodō, not the weakest technique but the first and perhaps most representative,” Tenkotsuki explains, beginning in her typical roundabout manner. “Unlike the system of numbered kidō that shinigami rely upon, Ura Hadō rely not on overwhelming power for their effectiveness but rather overwhelming force of will.”

“In the common tongue please, vixen,” Rosa chides, crossing her arms testily.
>2/3

“Ura Hadō is an outgrowth of what one might call an “arms race”, among beings who could literally write their will upon reality,” Tenkotsuki summarizes. “As such they may have a destructive effect more similar to a kidō spell much lower than the degree of difficulty and effort involved would suggest, but they will harm any being so long as the user's will is strong enough.”

“Meaning if you have the willpower, you can kick Susano'o in the balls and even he'll feel it,” Rosa adds. Rosa, answering the REAL question here.

“Strictly speaking, no,” Tenkotsuki replies with a frown. “But you could perhaps set him on fire, and then start kicking him. Whether that is a good idea or not... let us simply remind ourselves that “can” is not the same as “should”, and move on.”

>So by learning this technique I'll be stepping into a “balance of power” of sorts?
>Are there any other caveats that I should know about before proceeding?
>What does the “Saishodō” do, and why should I learn that technique rather than any other?
>Cool, but you had me at “new technique”. Where do we begin?
>Other?

>Are there any other caveats that I should know about before proceeding?
Gotta know it all.

>So by learning this technique I'll be stepping into a “balance of power” of sorts?
>Are there any other caveats that I should know about before proceeding?

>“I take it you're not talking McDonald's.”

>“Though it would not surprise me to find one in Hueco Mundo, no,” Tenkotsuki sighs.
kek

>Are there any other caveats that I should know about before proceeding?
I take it the second I learn this people will start poking at us.

>Are there any other caveats that I should know about before proceeding?
>What does the “Saishodō” do, and why should I learn that technique rather than any other?

>>Are there any other caveats that I should know about before proceeding?

>>Are there any other caveats that I should know about before proceeding?
>>Other?
Should we base assumptions on how this works with reiatsu clashing with one another as an example? Like, superior willpower "cuts" the lesser one so to speak?

It's never THAT simple, but it's also not an unfair summary.