The Invincible Undefeated Divine Sword Master is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Chosen by the divine sword as a “Natural Gift”–this guy is a warrior and invincible! Licht, an illegitimate son of a prestigious aristocrat was exiled from his family for being incompetent… Unstandardized magic, Absolute swordsmanship and the ability to pull out the Legendary Divine Sword. Licht, who went on a wandering trip, met Ariarose, the princess of the Kingdom of Ratculus, who was traveling to help others. Impressed by her noble ideals, Licht swears his loyalty to the princess! As a “Bodyguard” of Ariarose, Licht enrolled in the Royal Academy. When the vicious Devil’s hand lying in the Academy approaches Ariarose, the real power hidden within Licht will be released!