description says 100 million years while translation says just one million. Both are absurd, but 100 million is ridiculous. Humanity isn't even a million years old. This kid is going to be living and training in another world for the equivalent of thousands of lifetimes. Long enough for the planet he's on to change over and over. The fall and rise of civilizations, empires, cities, countries. Enough time for the top races of the planet to shuffle around. I guess the magic keeping him from aging has completely reconstructed him body into a god-like being for his body to be capable of perceiving and retaining any knowledge and experiences from such an absurd span of time. This poor kid is going to be mind shattered. After it's all over he's going to be like, "Wait,what?! This isn't my world! Have I finally died after a millennium? What is this place? A duel with who now!? I had parents!?"