No More Pain For This Villain. - Chapter 314 Phantom Chamber -5

A chance to change, to challenge destiny, making dreams a reality, and live a legend! A regular man gains a system that allows him to turn into a fish!

- Description from Novelupdates

Reborn in the Naruto world, Shin Uzumaki finds himself in the doomed Land of Whirlpools. As a member of the Uzumaki Clan! Trapped in a world filled with war, betrayal, and unimaginable power, Shin’s survival seems impossible.. Until it isn’t!![Ding! Replication System Activated!][Daily Login Reward: Common Replication Card.]​​​​​​​[Newbie Gift: Perfect Sage Body—​​​​​​​Adamantine Sealing Chains​​​​​​​—​​​​​​​​​​​​​​Four Symbols Seal​​​​​​​]With the power to Copy any Ability—whether it’s the Kekkei Genkai or Rinnegan or Forbidden jutsu—Shin begins his journey to dominate the Ninja World. [First task: Save Kushina and prevent the destruction of the Uzumaki Clan.]

A 30-year-old NEET is reincarnated into the body of an otaku that choked to death on instant noodles. As he comes to grips with his new life, he realizes that this world is subtly different from Earth. The denizens of this world are far better looking, and this new world also possesses futuristic technology as well as mysterious Yin Yang masters!

Two heroes of the game Legend of Heroes 2 who were rotten waters*.