Just thinking that:
_ Gokei has been said to know every single tactic on the face of the earth
_ Gohoumei certainly hasn't come up with the Ryuudou himself, since at least Riboku knows it as well
_ Gohoumei and Gokei are shown to share modus operandi, so it means the dad taught him something
Logic wants that, if not both, at least one between Reiou (Houmei's sensei) and Gokei (Houmei's dad) knew the Ryuudou and passed it down. Gokei is clearly the most likely one although there's margin to think Reiou did as well. But yeah, if it's just one, it's Gokei.
you've certainly shown as much with the implication of those pages you posted as evidence
The most knowledgeable in Wei and knows no less than 100 tactics (not all on earth exaggeration-kun) sure, but doesn't guarantee knowing the Ryuudou. Besides, it would've been very convenient if he pulled that out against Duke Hyou's charge hmm?
Share MO in what, the grinding part or their revenge/butthurt vibes?
Reiou is out of the question, since GHM himself says the only other one that knows and can execute the formation is Riboku, Reiou was alive and in jail so ...
while i won't be using it as a hard evidence, it's pretty much a given that someone knew about Ryuudou and pass it to GHM. It just doesn't make sense that someone from different country make an original technique that is the exact same thing, so someone must have used it before, and most likely it will be Gokei and/or Reiou.
GHM first used it in coalition arc, so it's impossible for Riboku to know it from GHM and try to learn it.
Riboku also first used it in coalition arc, so it's impossible for GHM to know it from Riboku and try to learn it.
although people can argue that Gokei doesn't have it simply because Gokei doesn't use it vs Duke (which , at that point, I doubt Hara even have that technique idea in his mind)
Riboku is always gathering information, it won't be strange for him to know about it from searching past records and then trying it himself
To be fair, GHM was speaking out loud - he can't say "Only me, Riboku and Reiou" because Reiou is meant to be killed. Though I don't think Reiou can use it either - doesn't seem like his style
Reiou is an offense oriented tactician, a technique like Ryuudou doesn't fit him very well, so if it's between the two of them then I see it coming from Gokei.