He is Lovestruck in the Revenge - Chapter 22 - 021: Flower Chamber Hall - Xie Family

As an international mercenary, Feng Luo entered a technologically advanced parallel world during a mission.

After living several years in the new world, an online sci-fi game called War became popular across the entire Star Federation.

Desert Eagles, Barrett, AK-47, Apache, RPG… One after another, familiar gears awakened his memories of the past!

Terminator, Zerg, Resident Evil, the Force,… The missions that appeared after a system update made him even more suspicious and shocked! As such, Feng Luo entered War and became a sniper.

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.

This novel is also known as Retrograde Gaming

Due to not being able to buy a game helmet, diabolical Li Huailin made a determined effort and made his own game capsule entering into the new online game 《Heart of Glory》. But he didn’t think that he actually got his game character stuck as a bug.

Other people get experience from fighting monsters, he loses experience from fighting monster; Other people get experience and money from doing quests, not only does he lose experience from doing quests, he even loses money.

Right when he thought that he couldn’t play this game anymore, his character died once and his experience suddenly skyrocketed. And thus he was enlightened…

If you don’t seek death then you won’t die, to level up Li Hailin started his life of desperately seeking death.

- Description from Novelupdates

A biker tries to save a cat on the highway and gets hit by a truck (Truck-Kun), he was rushed to the hospital but, due to internal bleeding, he dies only to be reborn as a cat, in a new world with a system.

In this new and vast world, he tries his best to get used to his new body and get stronger along the way. With his overpowered system and skills. To one day become untouchable.