Naruto: Starting with Infinite Chakra - Chapter 194: The Eight Gates Technique

In a world where strength is law and the weak are trampled, Ezra Cain was destined for nothing—crippled, abandoned, and left to rot. But when death comes knocking, something awakens within him.[Primordial Evolution System Activated.]A forgotten power lost to time, capable of infinite growth, limitless evolution, and ultimate domination. From the ashes of his former self, Ezra begins his ascent—devouring monsters, absorbing abilities, and forging a path no being has ever walked. But power comes at a cost.Ancient gods stir in fear. Forbidden realms tremble. The strongest beings in existence move to eradicate him before he reaches his full potential. But Ezra is no pawn in their game—if the gods wish to stop him, then he will do what no one has dared before.He will evolve beyond them. He will devour them. He will become the first Primordial Overlord.The age of gods is over. His reign begins.

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

Then placed into a high-school setting, Lin Yi is tasked by the chairman of a top-tier multi-billion company with bodyguard duty for non-other than his own daughter, a certain little Miss of said high-school.

His enemies, once ranging from drug lords, mafia bosses, political figures, and national leaders, are soon replaced with spoiled kids who happen to have rich papas and mamas, and Lin Yi finds his intense expertise and high-threat skillset misused, and very underwhelmed…

But he does get a harem cast as diverse as his old enemies, so Lin Yi decides that, for the sake of messing around with girls as an invincible entity in a down-leveled environment, leaving his bloody and death-filled war days behind is something he’d definitely want to strive for.

- Description from Novelupdates

A magical 'Universal Toolbox' led Joe Ga into the arms industry.The complex and unpredictable nature of the world caused Joe Ga to gradually change his goals...“Sir, how did you end up here?”“I don't know, I just wanted to make some money at first, buy a house, marry a wife. But slowly, as more and more people appeared around me, my goals started to change.”“So what are your goals now?”“Now, I just want to retire peacefully with my guys, really!”

With the ability of the King of Silver, the first king in “K”, to be immortal and immortal, he crossed into the world of One Piece. Although he became a Pirate, he did not target One Piece.

His goal is to live freely on the sea, it’s that simple.

- Description from novelbuddy