#honestly i wasn't expecting anything interesting other than maybe some bad synonyms or omitted kanji

[littleeyesofpallas]

I fell down a real rabbit hole with this one...

I realized that for all my poking around the names of shinigami and their swords, I haven't touched on many non-zanpakutou techniques or titles for the shinigami. So, initially, I JUST wanted to take a look at Yoruichi's kind of randomly revealed, involuntary final form Shunkou Raiju-Senkei Shunryuu-Kokubyou-Senki[瞬閧 雷獣戦形 瞬霳黒猫戦姫], which Viz has printed as...

"Shunko, Raiju Senkei, Thunderous Black Cat Battle Princess,"

...and you'll notice nearly half this title wasn't even translated. So, I had to go back to the first time they translated Shunkou Raijin-Senkei[瞬閧 雷神戦形] as "Shunkou God of Thunder Battle Form" (which you will note is both not quite the same name as the later form) but also that even that fell back on Shunkou as a returning term... so, I had to go back to the last time that one actually got translated as well... And this led me into a whole mess of things surrounding Shunpo in general.

SO. Starting at the very beginning of this tangled mess...

Shunpo[瞬歩], weirdly enough I can't find an official English translation from Viz? They just keep referring to it as romanized Japanese, "shunpo." I feel like the general agreed upon English in fan translations has been "Flash Step." That's pretty apt all around, only clarification is that it is, "[in a ] flash" as synonymous with "in the blink of an eye" and does not reference the actual act of flashing as with a light. It can also be translated as "[in a] moment" to the same effect, or in some contexts, "[in an] instance/instant." This will come back up later...

The broader category of shinigami footwork is apparently called, Hohou[歩法] with the same po/ho[歩] from Shunpo, plus [法] meaning "Way" or "Method." Very literally the "Way (of) Stepping" or "Walking Techniques."  For whatever reasons, Viz called this "Fast Movement."

Honestly, we don't actually see much lateral details to that system as everything we see basically just builds on the Shunpo.

Yoruichi is also referred to be the epithet, Shunshin[瞬神], with the shun[瞬] from Shunpo and [神]: "God."  Again, Viz went out of the way to fiddle with it, calling her "Flash Master" rather than "Flash God" but maybe that was a more deliberate secularization of the term. Since I had trouble finding the first use of Shunpo, I can synthesize a semi-official translation from Viz as Shunpo↝"Flash Fast" taking from their Shunshin:"Flash Master" Hohou:"Fast Movement." It of course sounds silly.

With Sui-feng we get the Shunkou[瞬閧] technique, which Viz translates as "Instant War Cry," ditching the "Flash" translation now. They seem to have gotten the [閧]:"War Cry" bit from [閧の声], which does in fact translate as "War Cry" or "Victory Shout," or more literally, "Battle Voice." Given the way Yoruichi first uses it, I think the implication is that the "Battle Cry" sound the name evokes is the sound of thunder from her lightning based Shunkou. Becuase if taken literally, Shunkou[瞬閧] means something like, "Instant Battle" or "Flash Battle" which is a little silly, and redundant.

When Yoruichi starts to ramp things up in the fight against Askin, she whips out the more refined, Raijin Senkei[雷神戦形], which Viz called "God of Thunder Battle Form," likely to mirror the chapter titles, God of Thunder. Raijin[雷神] is in fact a Japanese god of thunder and lightning, and the name means "Thunder + God." Raijin wears an iconic ring of drums which account for the sounds of rolling thunder. Yoruichi's Raijin Senkei form emulates that shape, and the phrase [戦形] is straight forward enough, meaning "War Form" or "Battle Style." But [戦] is not the same [閧]:"War/Battle" in Shunkou, though.

So when Yoruichi goes beast mode, her technique changes to Raijuu Senkei[雷獣戦形], where [戦形] is still "Battle Form" but Raijuu[雷獣] means "Thunder Beast/Animal." But that's not all!

The Raijuu[雷獣] might be a really obvious combination of two words, but it actually refers to a specific mythological creature, said to descend from the sky in a bolt of lightening, with a roar like thunder, accompany the god Raijin, and to resemble any of a long list of animals, but usually something like a 2ft long wolf, or cat, or weasel or even badger. (personally, I have a sneaking suspicion that if this was based on sightings of an unusual real world animal, then given some of the mythic behaviors and descriptions, I think it was a wolverine from the northern mainland) It's also often described as having either ashy gray or deep red to black colored fur. Also some versions describe them as almost chimerical fusions of other animals, else with totally uniquely fantastic anatomies.

So finally we get to the final epithet of this involuntary technique, what Viz called, "Thunderous Black Cat Battle Princess," Shunryuu Kokubyou Senki[瞬霳黒猫戦姫] which breaks down into...

Shun[瞬]: "Flash/Blink/Instant" as we've been using...

ryuu[霳]: ?????*

Kokubyou[黒猫]: "Black + Cat"

and Senki[戦姫] (-ki[姫], NOT -kei[形]) "War/Battle + Princess"

*And now that we've gotten all the way back to where this odyssey started... we can actually address the first and BIGGEST oddity in this whole thing...

THIS KANJI ➪ 霳, which is definitely NOT just the word "Thunderous"

But apparently it just doesn't have any kind of a translation???? What's odd is that it has a pronunciation guide so it's not like it's a Chinese only character. It appears that it IS a word used in Japanese, I just have no idea how... I also couldn't find any compound words that use it, to try and glean some kind of commonality out of them. I only had two feeble leads... the first was the composition of the kanji itself [雨] and [隆], which mean "rain" and "noble"/"prosperous," respectively. But kanji aren't always just the most straightforward combination of their etymological parts, so I don't trust that to really tell me much on its own.

My second, more obtuse lead was weblio's suggested "similar to..." words, which were as follows:

[露骨になる]: meaning "to become conspicuous"

[露骨に言えば]: "to be plain/frank with you" "to speak openly"

[露髄]: "exposure; dental pulp exposure"

Two of these share the root [露骨]: meaning "unconcealed/undisguised/blatant" or "broad/lewd/indecent," from [露], which is also a root of the 3rd, and in this context I assume means "exposed/scanty/bare/unconcealed/naked​." Oh, and [骨] means "Bone." So "to be conspicuous" is literally "to expose bone;" "to speak openly" is to "speak [like] open bone;" and the last one is literally "open marrow."

[霹靂]: "thunder/thunderclap/bolt/bolt of lightning/thunderbolt"

[霹靂神]: "loud thunder" (and you'll notice this is just adding "kami/god/spirit" to the end of the previous word for "thunder")

[霽]: which appears to mean "to clear up [after a rain]" (although some of the dictionaries i checked had conflicting entries, or lack there of)

Now, there's a common thread in some of these... They all are written with the radical [雨]: "Rain." This relates rain to storms to get [霹]: "thunder" and is where [露] means both "dew" and "clear away ((as if) by rain)," and the "washing away with rain" bit turns into a more metaphorical and general act of, "laying bare" or "exposing." And arguably a "noble or prosperous rain" could be said to describe a clearing or cleansing rain, not unlike [露].

SO! On the one hand, it could be that Kubo just reached so deep into obscure kanji trivia that a non native speaker like me just has no chance of figuring out what hyper specific context or source he pulled it from, so it means exactly what he meant for it to mean, and I just don't know what that is... But there also a chance that he actually used the wrong kanji altogether; and maybe that seems a little flippant an accusation, but he has done it a few time in serial before --Although in those cases he, or at least an editor, fixed them for tankoban print.

I get the feeling Kubo was looking at something like a very narrow margin dictionary for cool words, looked at the very similar complex kanji next to each other (霳 露) and just let his eyes waver across maybe one and ended up picking the wrong one.

(oh shit, wait... i was only saying that to paint a picture, i didn't mean it literally, but i when went back to check something, I hadn't noticed before, but the kanji Kubo used and the one I'm talking about are literally RIGHT next to one another in the unicode database...)

Anyway! Finally drawing a conclusion from all this... Given Yoruichi's repertoire of lightening themed attacks, it's tempting to think that maybe the easiest explanation is that he meant [瞬霹] to mean "Flash Thunder." But considering the adjacency of the "clearing rain" terms it could be that Kubo meant [瞬露] to mean something like "Flash Exposure" or "Instant Lewdness" as a play on both the rain, storm, and lightning theme and Yoruichi's scantily clad feral combat form. So, what I think all my fiddling around has determined is that the full final form technique name should read,

Shunkou [瞬閧]: "Flash Battle-Cry"

Raijuu [雷獣]: "Thunder Beast"

Senkei [戦形]: "Battle Form"

Shunrou [瞬露]: "Flash Exposed/Lewd"

Kokubyou[黒猫]: "Black Cat"

Senki [戦姫]: "Battle Princess"