Rise of the Lowborn: Ascending the Ranks by Crushing Incompetent Nobles, Vol. 1

Hazen Heim is a newly appointed imperial military officer who had the poor luck of being born without a silver spoon in his mouth. This means that instead of landing a cushy nepotism gig, he's being sent to the front lines to deal with the worst of the worst. Awaiting him are scumbag supervisors who constantly steal credit, low-life leaders who love to abuse their power, and bumbling members of the brass who have never had to make a hard decision once in their lives. Fortunately, Hazen racked up decades of knowledge and experience in his past life as a legendary mage. Now it's his turn to put the tyrants in their place, and they're going to learn that when they go low, he goes lower...