Seirei Gensouki: Spirit Chronicles Volume 17 by Yuri Kitayama

One fateful day, a kingdom on the edge of the Strahl region was destroyed by a black-haired saint named Erica. After leading a revolution and becoming the first ruler of the newly formed kingdom, she immediately marched on to the next major nation without so much as a brief respite—all for the sake of her own desires.

Meanwhile, after events unfolded in the Galarc Kingdom, Rio decides to return to the Yagumo region to update his friends and family of the outcome of his battle with Lucius. But will an unexpected reunion along the way spell fortune...or disaster?