The Live-in Son-in-law of a Prestigious Magic Family is a Transcendent Sword Master

The Mage's Natural Enemy. The Wandering Mercenary. I, Reagan, was called that. "I heard you're quite skilled with a sword." To me, the last survivor of the renowned magic family, the Count of Benheim, approached. I was hired by the resistance to defeat her enemy, the Demon King of Magic. And the final battle. "If you survive this war, please help rebuild the Benheim County." Instead of surviving, I regressed. And became the son-in-law of the renowned magic family.