The Fief Heir's Realm Rewrite

Warren Voss transmigrates as Fief Heir. Father killed, Uncle Quinn plots, emperor uses him. Dismissed as useless, he seizes power, reorganizes army, develops new weapons, humiliating officials. Northern Steppe Khanate invades, he defends border city, snipes Khan. Princess Mia, betrothed, is won over by his resolve, fights alongside him. A treacherous wedding massacre hides a secret: the enemy is on the imperial throne. Warren vows to avenge father and rewrite realm's fate.