Continued, my thoughts on Shinou & Soushi from Episode 76:
I think I figured out what Shinou was trying to do with Shouri. Shouri is desperate to protect Yuuri and willing to do almost anything to get enough power to protect Yuuri. Perhaps Shouri is a back-up plan--if Shinou/Soushi can't take possession of Yuuri, then Shouri should be willing to cooperate if it gives him the required power to protect his little brother. That is what Soushi part of Shinou is hoping for at least. I think the good part of Shinou, and I do think he is in there buried beneath Soushi right now, hopes that by getting Shouri started using his powers, that Shouri will learn to get them under control soon enough to help Yuuri--possibly even for Shouri to use Morgif on Shinou/Soushi.
I think a lot of Shinou's actions can be seen in two different lights--depending totally on your point-of-view. Shinou and Soushi obviously were both sealed in when Shinou's soul was sealed, so there are the two of them guiding Shin Makoku using the Original King's 'voice' - so you can never really know which one was making to decision and therefore if it was really for the good of the country or not.
For example, bringing Shouri to Shin Makoku and awakening his Majitsu. As I previously noted, there are two ways to view this action: Soushi - giving Shouri power will him a taste of what true power can do, making Shouri want more power to protect his brother with, making him desperate and willing to do anything to get that power--like working with Soushi; or Shinou - bringing Shouri gives Yuuri a powerful ally and by awakening his majitsu, he is only making Shouri a more powerful ally, and since Shinou knows that Yuuri is going to have to fight Shinou/Soushi, having a part of Yuuri's family close-by will give Yuuri strength when he needs it.
See, Shinou/Soushi was responsible for bringing Shouri to Shin Makoku and both sides of Shinou/Soushi had different reasons why they want Shouri present. Each side saw different advantages to bringing Shouri to Shin Makoku because they each look at the world differently. Soushi sees power--I'm borrowing a favourite quote from one of my favourite TV shows, "Charmed", to explain how Soushi sees the world "There is no good and evil, only power," evil!Wyatt Matthew Halliwell, which is exactly how Soushi sees the world--he views people in terms of how much power they have and whether he can use that power or needs to remove it as a threat. In my previous post, I explained why Soushi would think Yuuri weak because of his pacifist nature and therefore someone that can be easily controlled. After all, hasn't Shinou/Soushi been manipulating Yuuri to do exactly what they want since before he was born? Yup.
So, in terms of power, both Yuuri and Shouri are useful to Soushi--they each have great power in their bodies and Soushi sees their wills as easily manipulated.
Shinou also respects power, but he also knows that power is not the only kind of strength and that power alone does not make a man great. Shinou himself is a perfect example--he has immense personal power, yet he knew that he alone could not defeat the darkness that is Soushi. He sought out the Sage, yes, because he was powerful, but also because Shinou knew that, alone, he wasn't smart enough to win, but with the Sage it was more probable. Also, all the people Shinou brought together to fight came willingly, with no one forcing them to join just because they were powerful, like Soushi would. Shinou recognized that an individual's willing cooperation is what separates the powerful from the truly strong. A powerful person who is unwilling is worth less than an average person who is willing to give it their all. Case-in-point: Conrad's ancestor was only human, had no where near the power that any of the Mazoku possessed, and yet because he fought with all his being, all of his heart, he was just as strong and useful as the Mazoku.
Shinou understands that a person's heart holds great power, but it is an intangible power, something that cannot be seen unless it is looked for, unlike a tangible power, like Majitsu and Hojitsu, which can be seen by everyone and felt by everyone. Caring about someone is both a strength and a weakness and because Soushi can't physically see the strength a person's heart creates, he doesn't understand it, and therefore dismisses it as power, seeing it only as a weakness.
An example of this is: Shouri & Yuuri. With Shouri and Yuuri, both brothers care deeply for each other and do not want the other to be hurt. This manifests in Yuuri in his commands for Shouri to stay out of the fight--he knows that without powers, Shouri is vulnerable and more likely to get hurt. Shouri is overprotective of Yuuri because he sees it his duty as an older brother to keep his brother out of danger and when that isn't possible, to protect his brother when he is in danger.
This desire to protect Yuuri leaves Shouri vulnerable to manipulation--which is what Soushi sees. Shinou sees this too, but also sees that, by putting Yuuri in danger, Soushi has not only given Shouri the motivation to become stronger by himself,he has also negated any offer of power that could have been made by them to Shouri. Yes, Yuuri is in danger and yes, Shouri needs to be more powerful in order to save Yuuri, but no, Shouri will not take power from the very entity that is endangering Yuuri.
Also, because Soushi doesn't really understand how the heart works, he misjudges what people will ultimately fight for. Like Wolfram--he is weak right now from his heart being removed, or more accurately, the essence of his heart being removed. Shinou/Soushi has observed Wolfram from his birth and has seen how he reacts to situations, and feels that, because he knows how he has reacted in the past, he can accurately predict Wolfram's reactions to the present situation.
But because Soushi doesn't understand why Wolfram reacts the way he does, how most of his reactions are self-defense mechanisms and he usually feels the exact opposite of what he says, he can't reasonably predict what Wolfram will do with the present situation--but Soushi doesn't know that, however, Shinou does. So the Shinou part will reinforce what the Soushi part thinks Wolfram will do: nothing, just stay and recover at the castle because that is what a selfish and obnoxious prince would do and has done in the past. But Shinou knows better and by reinforcing Soushi's false belief that Wolfram will not be with the party coming to rescue Yuuri, he is giving the rescue party a better chance of aiding Yuuri and ridding Shinou of his possessor. He is also keeping Soushi from knowing that an extremely powerful and ticked-off fire-starter will be after them.
This misjudgment is also going to bite Soushi in the ass in the form of Murata. If Soushi truly understood what drives the Mage's heart, why he joined Shinou in the fight against Soushi, he wouldn't turn his back on Murata and not trust him. But, again, because Soushi is going only on what he has observed in past behavior, he knows that when in comes to Shinou, the Sage always keeps his promises and, since that is exactly what Murata has done this time, he thinks that he has Murata's loyalty and support. He does not expect Murata to betray him because the Sage has never done so in the past and Soushi sees no reason for Murata to betray him.
I assume that Murata is to rule the world alongside Shinou/Soushi--he is being offered the greatest power, the power to rule the world, so why would a powerful person like Murata not want more power? Because Soushi sees the world solely in terms of power, he can see no reason to doubt Murata, whereas if Soushi understood the human/demon heart even a little, he would be a whole lot more wary of Murata--just like he should be. Again, the good part of Shinou is reinforcing the Soushi thoughts, telling him that he absolutely correct--that is exactly how the Sage will act--when Shinou knows the exact opposite is true.
I believe that this is why Shinou seems to have accepted and welcomed Soushi's possession of his soul: by agreeing with Soushi, reinforcing Soushi's gross-misjudgments of human/demon nature, and influencing Soushi to actions that Soushi believes is in his best interest but truly aren't, Shinou can actually help his people without expending the energy to fight a possession that he knows he has already lost. This way, all his energy goes to helping his people and he is reinforcing Soushi's false beliefs in humans and demons in such a way that decisions based on these beliefs is actually beneficial, not detrimental. Shinou is doing the only thing he can--try to weaken Soushi from the inside and have faith in the human/demon heart--that it can overcome anything, even the evil that is Soushi.
The Weak Maou that Shinou has helped, along with Murata, Soushi to think Soushi has manipulated into existence will be Soushi's downfall. Yuuri was born on the other world because of the danger from the war--a war that I am sure Shinou/Soushi helped to bring into existence, just as he helped Cheri bring his three keys into existence in the same generation, in the same family. In this same convenient war, the most peaceful and loving of the Mazoku--one that just so happens to be from the 4th key's family, when the 3 other keys have already been born to the Maou--Susanna Julia, is told she will die and then her soul will be reborn as the next Maou, who will finally bring peace to Shin Makoku. Then, amazingly, she dies--actually lets herself die--in the next battle of the war.
And here is another stopping point because I have wrote way too much already and if I keep going, I don't think I'll ever stop. And I am tired, falling asleep im my chair.