MTL - Naruto Lineage Theory? Trash - Chapter 150

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

Way, way, and very way before I was even born, my world was invaded. Actually, not just my world, my entire damn universe was overrun by another, led by a single race that called themselves the Eternals.And they were prepared. Very prepared. Every life we lost in the war against them was used by them. They didn’t just kill people, they captured their souls, forged them into Phantoms, and used the souls to twist beasts into Abominations. Our dead became their army.Three hundred years later, I was born. A guy with way too much energy. Sitting still? Impossible. Taking it slow? Not happening. I was always moving, always ready to burst into action. Then I awakened, and got a talent too.My Talent's Name Was Generator.Because of it I never ran out of energy. Ever. My muscles? Supercharged. My healing? Faster. My stamina? Please, I had no idea what being tired even felt like.So if the universe wanted to throw an endless war at me?Fine. I’d throw everything I had right back.I wasn’t born a hero. Never wanted to be one. But this war? It wasn’t just my universe’s fight anymore. It was mine. The Eternals made sure of that when they took my parents' souls.

What would you do if you could control and use your Karma?

Liola—the best assassin in his world—has vowed to kill no more. He was being chased by an assassination organization when he accidentally dropped into a parallel universe: through a dimensional gate and into poor teenager Kaiser’s apartment. Instead of going to the government shelter for lost dimensional travelers, Liola and Kaiser wind up going to school together.

Liola has been trying his best to live the life of an ordinary person, but after certain things happen one after the other, he begins to realize that being an ordinary person could be harder than being an assassin.