What is the secret of Sei Dou Goui? Well first let's talk about Ogata's training method, specialization training. Specialization training develops the disciple's talents and strong points. Ryuto's greatest talent is his inner eye, so it's safe to assume, if he went through specialization training it was to develop his inner eye. So how did Ogata develop Ryuto's inner eye? Matsuena hinted at how in the pic below, through symbolism:
The important part is what's said about the Norse God Odin: "He sacrificed one of his eyes at Mimir's spring of knowledge where he gained the power to foresee." What happened to Ryuto after he used Sei Dou Goui? His sclera turned black and his pupil turned purple. See what I'm getting at?
I could be wrong about Ogata intending for that to happen, as it could be an accidental effect, but who knows I could be right.
Edited by ki0, October 28 2017 - 06:25 PM.