Mitou Shoukan://Blood-Sign - Volume 4, Ending X-01 - Waking From a Dream

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

He doesn’t want to be wanted for bounty, or be a pirate, but if there’s no other choice, he can only become a pirate…..

Let the world turn upside down!

- Description from Novelupdates

Meloni is just a musician. A normal, charming girl whom everyone loves and admires. But she has a secret; she can manipulate sound.For years, she managed to live with that secret, until everything came crashing down when her resonance was picked up by local organizations.In the midst of all the chaos, whether she should live as an awakened conduit or just a normal person, she ends up rescuing a small black bird.But that bird, is someone the whole world is afraid of.

Following a brutal and tortured death, a former assassin, known only by his codename Kuro, is given the opportunity to reincarnate in another world, a world with magic and monsters. Armed with an unrivaled healing factor and an inhumane pain threshold, Kuro opts to go for a reckless direct approach in this world instead of a stealthy and cautious one, and as a result, slowly gains attention bit by bit.

Having previously been a loner in his old life, he interacts and befriends people for the first time in his existence, however, his blunt nature also sees him making just as many enemies, both big and small. By combining his old assassin skills with the magic powers of this world, along with his high resistance to pain and rapid regeneration, he doesn't take long to establish himself as a formidable force in this world.

Initially, Kuro only faces minor threats, like weaker monsters and bandits. But before too long, the threats slowly but surely become more and more severe…from Zombies to a bloodthirsty empire to Vampires and Demons, and even divine beings…however, as the enemies he faces grow stronger, so does Kuro, gaining rare powers that have never or rarely ever been seen in this world…