So What's Wrong with Getting Reborn as a Goblin?, Vol. 7 (manga)

Akira has come a long way: from Japanese salaryman to goblin mayor to goblin baron! But with nobility comes conflict, and Akira's first taste of war is bitter—his foe, Count Gignas, has dispatched an army of hypnotized goblins against their brethren in Akira's village. All Akira's skills are of no avail, and he can only watch as the helpless goblins die in droves. But as his motto—“I must not repeat my mistakes”—burns in his mind, a new skill bubbles up from within…