One Piece: From the Start, I Got the Thunder Fruit Sign-In, and Became a Natural Disaster

“Still busting your back training Haki and developing your Devil Fruit? I just use sign-in! [Ding! Sign-in at Foosha Village, reward: max-level Observation Haki!] [Ding! Sign-in at Shells Town, reward: max-level Armament Haki!] [Ding! Sign-in at the Baratie, reward: swordsmanship grandmaster trial card!] I start with the Rumble-Rumble Fruit, with no weaknesses and no fear of the sea. The destination others risk their lives to reach is just my starting point. This is an overpowered power fantasy from beginning to end. No training, no frustrating setbacks: sign in to get stronger, and hit the peak from the start!”