MTL - My Cold Gentle Husband - Chapter 719 found it

Have you ever thought a monster that has a job of a summoner and a tamer

what should it call itself Monster Summoner? Monster Tamer? but he itself was a monster too

Watch as our mc travels the world as an reincarnated human who turn into a monster

I am the sword.
Killing a man amidst a thousand miles, no one dares take ten steps.
Killing a man amidst a thousand miles, no one can take ten steps.
Killing a man amidst a thousand miles, ten steps? Not possible!
I am the sword, the sword is me,
On the path towards heaven, each shall wield their own.

She is a top-class spy, a poison specialist, but also a young and cute girl with a sinister temperament. In spite of her sweet and innocent appearance, she can complete any tasks without the slightest hesitation. One day because of an incomplete black magic, she was sent into the body of a girl who was deemed as a good-for-nothing. What kind of change will she bring to this continent?

A Prince said with bitter hatred, “I thought she was weak and easily bullied, therefore I broke off the engagement. I really didn’t expect she is such a shrewd girl. I made an error of judgment.”

The Crown Prince deeply sighed, “She is such a sexy evildoer! Obviously, she has a frail and tender body, but I am not able to overwhelm her…”

Finally, an Emperor hit the nail on the head, “She is just a bit two-faced!”

She answered, “You’re just a big pervert!”

The Emperor carried her into the room and said, “You are predestined to be mine! A two-faced girl and a pervert are a perfect match, right?!”

- Description from Novelupdates

The world experienced a cataclysmic change, and countless spatial gateways appeared out of thin air.

Exotic beasts of all shapes and sizes swarmed out of those aforementioned spatial gateways, forcing the humans to face the crucial moment for their survival.

In order to search for a chance at survival, brave warriors from the army and scientific researchers risked their lives and entered the world beyond the spatial gateways. To their surprise, they discovered that there was a chance of obtaining beast cards by killing these exotic beasts in their world.

Those with extraordinary spiritual strength are able to utilize the beast cards, perhaps transforming the cards into the beasts’ combat bodies while they were still alive, or transforming them into weapons or defensive gears, or…

A new occupation came into existence following the changes, known as beastmasters.

A transcender with two souls fused into one found himself in this magnificent new world full of waves, rising step by step as he ascends into the seat of a godly beastmaster.

- Description from Novelupdates