I'm Sailing, and My Attributes Double Every Day

Allen traveled to the world of pirates and turned into a 6-year-old child who was adopted by a person with the surname "d", but could only work as a busboy in a tavern. Ten years as a day! Finally, when he turned seventeen, the attribute doubling system was turned on. Constitution, strength, agility, defense, spirit... A random attribute is doubled every day! Physical fitness doubled! The most durable man in the world! Double the power! One punch shatters the overlord's color entanglement! Double your agility! Kizaru, have you ever been kicked at the speed of light? Defense doubled! I stood and let the sun god Nika fight for three days and three nights without losing any blood! Double the spirit! The strongest overlord color directly stuns red-haired Shanks! ... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.