Who needs magic anyway? WNMA

Ruak is a "defect". A commoner's whose element is inactive, making him unable to use the mana flowing in his blood. People like Ruak are usually doomed to low working jobs, homelessness, and are at the bottom of the caste system, but Ruak won't, CAN'T accept that as his fate. Tredor Academy, an academy that accepts anyone and everyone, even defects like him, Ruak isn't just joining the academy to work as a cashier or a trader, no Ruak is determined to be in the mixed magic combat unit and to become a mercenary, he might not be able to use his element and has the world against him, but he has something they don't, rage, a actual demon and an undying? Determination to see the kingdom burn and rise better from the ashes
WARNING-Bullying, mature language, mental health, and other mature topics are contained in this story, no plans on smut as well.
WARNING-MC is NATURALLY weaker than his peers and will counter that will smarts, sadism, and hard work. If you're looking for a system, or a Harem THIS IS NOT YOUR STORY.
NOTICE-Please read the auxiliary chapters, as they will explain the elements and their level of mastery., and also will briefly explain how mana and runesmithing work as it's different from the usual.