Warm Wedding, CEO Loves Me - Chapter 5

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

- 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.

Apocalypse befell, and roommates performed a skyward ritual.As the fog descended, the Book of Blood Spirit appeared in the hands of all survivors, and only those with a Contract monster could survive.Su Han directed his gaze to the neighbor who had already mutated and twisted, silently pulling out a gleaming fruit knife...Grotesque meat corpses, giant spiders with gaping mouths, eyeballs enveloping the city, one-eyed sharp-toothed hand monsters...Civilization fell, cities shattered, and all humans became meat for the monsters. There was only one way to survive:Use monsters to fight monsters.

After a shocking reincarnation, our hero opens her eyes to a new (and messy) world the last thing she remembers is reading Lady Viper’s Vow, a dark fantasy novel about a cruel, misunderstood villainess and her path of doom. But when our protagonist finds herself reborn right in the heart of an attack, she’s moments away from a second, way-too-soon death. Just as she’s about to face the end, a mysterious “system” pops up with a single mission: Level Up or Die Trying. It’s bossy, snarky, and her new best friend. As she levels up into a borderline-cheater powerhouse, she discovers her fate isn’t to be a hero, a princess, or even a sorceress, but to protect the one person no one ever expected her to side with: the villainess herself.