The Great Cleric 10 (manga)

Reconstruction of the Yenice Healers' Guild is finally underway thanks to the help of the guild's new, unusually skilled slaves, and Luciel is eager to rebuild the healers' reputation. But at every turn, he finds himself face-to-face with Yenice Representative Sharzah, who doesn't exactly like him. With enemies lurking in the shadows and multiple parties out to get them, Luciel's plans might not go as smoothly as he hoped. Luckily, he has the power of Substance X on his side.