That Second-Rate Warrior Is Now an Overpowered Mage! (Light Novel)

Despite having become a warrior-class adventurer, Lars has long been looked down upon by the members of his party, and made to be their errand boy. Unable to tolerate their treatment any longer, he decides to change classes when he discovers that he actually has overwhelming magical power. Moreover, he's at a Platinum level: the same level as that of the greatest sage in history! Thus Lars begins his second life as a sage: sending dragons into oblivion with a single blow, triumphing over his former adventuring companions, and solving one problem after another with his extraordinary magical ability!