Yokoyoko is Shin's Akou / Tou [manga spoilers]
I have a theory that Tou originally was probably from some form of hermit/ independent/ wasteland village, especially with that extra chapter of his with his master/ father.
In some Rinko fashion, Ouki probably adopted him.
With Akou, we all know, he was a general from another doomed state Ousen helped bring down. Ousen shared his dream with Akou, Akou believed in him and his cause and joined him.
So, with Yokoyoko, I feel that the Hi Shin and former Han troops will integrate, with that, Yokoyoko would become a sort of tertiary adjutant (after En and Sousui), but he would be strongest and most capable.
I really hope that comes to be, because that will be an upscale as becoming that type of awe/loyalty/inspiring great general.
He already has that air(Yokoyoko) and responsibility. The last time we saw him bringing up the rear while also pushing Kaine back and keeping up with the rest of the army, and he also saved En by jumping into the fray at a climactic moment.
;
Now, with the possibility of Shin directly facing either Gaku Shou or Riboku or both, Yokoyoko is going to play a pivotal part as Shin's vice, considering that the morale of the Han will be one of the major factors to consider; not only that, but his eye for strategy would also be a major advantage.
Not only that, but it seems to me that Shin got Yokoyoko's respect during Eitei, and that moved Yokoyoko to join up with Shin, especially as other armies from Han went to Ousen as well. Yokoyoko stayed with Shin. I mean, yeah, we don't get to see his expressions, and there's some ambiguity on that point,
But Yokoyoko heard Shin speak of unification, the fire of will and the fire of life, and then saw him back up his beliefs with actions.
Any honourable man would respect that, including Yokoyoko
We see him witness both the speech and the backing with actions, i.e., Shin killing Haku'o koku, and then she chooses to lead the Han army.
He chose Shin, that's clear, the reasons are unclear though
He could have chosen to go with the guy he knows best, whose beliefs, dreams, and intentions are clear. and the guy who is most similar to Rakua Kan.
Meaning he could have chosen to follow Shin, as Shin is not like other generals who would discriminate against him and the troops, especially after Nanyou.
Shin has proven himself a worthy leader to follow, and Yokoyoko has chosen to follow him, in the same way Rakua Shou will probably become Kyou kai's lieutenant
