Saitei Rank no Boukensha, Yuusha Shoujo wo Sodateru Orette

In a world where rank defines everything, a forgotten legend hides in plain sight. He may look like an old man, but he is the strongest adventurer to ever walk the earth. Now, he takes on the lowest-ranked novice, a young hero girl, and transforms her into a living weapon of destruction. Witness the rise of a legend and the ultimate training regime! Dive into the story now—read Chapter 1!