MTL - Ace Evolution - Chapter 8 Alien Surge

A next-generation virtual online game, a hardcore gamer, a glitch that shouldn’t have existed… By sheer coincidence, Meng Jingtian ended up being the sole player god in a game. Thus, while ordinary players worked themselves to death running missions for NPCs to win their favor, NPCs prostrated before him! While ordinary players almost vomited blood grinding for gear so that they could solo bosses, the king of divine beasts kneeled before him, willing to offer its life and worship him. And while players went to suicidal lengths to trigger random events and lucky encounters, transcendent beings came to find him so that they could offer their precious treasures as tribute.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

Lucius Mc. Conol, once the leader of a ghost division, is captured and killed on a mission. However, not all is lost as he finds himself reincarnated in another world... as a leafling?

Join Lucius as he teaches lower leveled plant life human tactics, bringing to them new concepts and powers.

*Ding* [You've leveled up]

This is a kingdom-building, evolution story which sees Lucius encounter beings from different species, spreading his influence and 'mystical' powers.