Are we sure that's Utsuho?
I can understand if that is a tag taken off of Pixiv.
The legs look too large to be bare. More like pants.
My Guess is it is Mokou.
The hair looks like it is long enough to be her, and she also has a bow.
Keeps the red color and i can't see a sign of Okuu's arm cannon.

Kaito_Fugiwara said:

Are we sure that's Utsuho?
I can understand if that is a tag taken off of Pixiv.
The legs look too large to be bare. More like pants.
My Guess is it is Mokou.
The hair looks like it is long enough to be her, and she also has a bow.
Keeps the red color and i can't see a sign of Okuu's arm cannon.

From the top of the pixiv page.
「なに一人だけツナギで来てんのよ」「そうだな妹紅、スカートは　大事だ」「ぇ？　え！？」

While I can't read japanese, I can recognize that this, 妹紅, "means" mokou.

Kokoro controlled the (emotion of the) insane characters and put them under her control?

Very Effective.