The Dungeon Seeker - Volume 3 Chapter 5 part1

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.

《Live Action Murder Mystery》Case File:

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

Ruan Tian is a cat which gained sentience, and is infatuated with the goddess who once saved him. During the college class reunion, Ruan Tian once again confessed to her, but she openly proclaimed that she would only marry Qin Li and no one else.

Qin Li was Ruan Tian’s number one enemy and love rival, and he was born to put Ruan Tian down for a hundred years!

Ruan Tian looked at him furiously. “Let’s battle! Only one of us can remain!”

Qin Li: ▼_▼ Shall we get on the bed?

- Description from Novelupdates