This entire story is all over the place. He's supposed to be the strongest to the point he got bored and reincarnated himself. Yet he somehow conveniently loses his memories and powers only when the plot needs him to forget them. Now we have a villain who's supposedly so powerful he "owned" the MC in his previous life, which is entirely contradictory to the entire title of the story and the plot itself. He's supposed to be the first adventurer who upon attempting to register was immediately measured by the magic tool to be the highest rank from the very start, yet he rejects the offer because he doesn't want to be controlled by governments like a tool. Yet for some reason, nobody knows him across the entire Adventurer's Guild Association's top and officials, throughout the country as if they don't have any form of information-sharing or communication at all. I don't know the original novel for this, but this is all so random. The very nice art style is kinda wasted on it.