One Piece: Seaside System - Chapter 7: Marine Based -

What happens when a scientist from a futuristic world reincarnates in a World of Magic and Knights? An awesome MC is what happens! A scientist’s goal is to explore the secrets of the universe, and this is exactly what Leylin sets out to do when he is reincarnated. Dark, cold and calculating, he makes use of all his resources as he sets off on his adventures to meet his goal. Face? Who needs that… Hmmm… that guy seems too powerful for me to take on now… I better keep a low profile for now. You want me to help you? Sure… but what benefit can I get out of it? Nothing? Bye. Hmmm… that guy looks like he might cause me problems in the future. Should I let him off for now and let him grow into someone that can threaten me….. Nahhh. *kill*-

Alternative: Leylin is transported from an advanced technological era into a medieval world— except there’s magic. Equipped with “only” his quick wits and an A.I. chip fused to his soul, he sets out to become the most powerful magus the world has ever known. In a land divided into the Light and Dark Magi, the weak can either be cattle or disposable slaves. Only the strong can determine their lives, and only they have the luxury for virtue. Yet strength is only a tool for Leylin, like any other. His goal, in the end, is his own.

Kaelen Dragonyx, a boy who lost both his parents and his mentor in the most ruthless way possible, decided in his heart to become the strongest swordsman in the world to protect the last remaining family he had, which is the only child of his mentor and his childhood friend.But along the line, he discovered that he is the most talentless boy of the generation which made his road towards being the strongest swordsman to be much further away and daunting than he could imagine. Be he didn't give up until he stumbled upon a sword that drastically changed his fate.

Monsters appear frequently, instances are everywhere!When various classes shine brightly, Li Haotian awakens to what everyone considers the most useless Illusion God class—the Mechanic!But what others don't know is that Li Haotian's Mechanic can unlock a special talent every ten levels![Unlimited Ammo]When others are cautiously navigating instances, Li Haotian is already surrounded by countless Superpower Mechanical creations—Gatling guns, Rocket Cannons, bombers, Wolverines, Terminators, intercontinental missiles, Aircraft Carriers...and, unlimited ammo![God's Eye View]While others are carefully exploring the enemy's situation, Li Haotian is eating hotpot and watching the enemy gradually fall into the encirclement of the superpower army, grinning.[Air Drop Support]When the enemy is playing outdated tactics like blitzkrieg and encircling points to reinforce, Li Haotian remains calm, pointing to the sky—the superpower army instantly descends thousands of miles away, covering the skies of Sakura Country!Abyss Dungeon, Slaughter Dungeon, large group instances, international war instances... Li Haotian sneers and goes alone.Because, I alone, can rival a million troops!

The elf girl, Aria is an adventurer. Her enchanting, lovely features attracts everyone. Her twin peaks are ripened to the point of exploding. Then, being embraced in between those twin peaks was a little animal… his name is Tama.

He looks like to be a cat at first glance, but Aria and her surrounding companions failed to take notice of single detail. Tama, he’s a human who’d reincarnated, given a second chance at life. His true form, it’s not that of an ordinary cat. Instead, he’s a monster of the strongest class, an extremely young behemoth.