The Ossan Newbie Adventurer, Trained to Death by the Most Powerful Party, Became Invincible

In the magical world, it was saying that if you start your adventure at young age then you can get magical powers. At that age, you can also get more strength for your magic. However, all these were just rumors. Rick Gladiator achieved his magical power in his middle age. Not only got his power but also got the highest rank in the magic. He defeated all the other adventurers who considered him a fool. He also fights against many monsters.