You've Got Mail: A Cautionary Tale - Chapter 23 - All First Loves Are Painful

This is the story of a boy who lived a secluded life in the mountains, tending his farm, rearing his fish, and dreaming his dreams. Eh? Did I suddenly conquer all worlds and become the big boss? Or am I still in a dream?

- Description from Novelupdates

Ethen Cole travels to an era where everyone battles with pets. In a world revived by spiritual energy, danger and madness run rampant. Humanity relies on battle pet masters to establish bases and unite for survival.Before the college entrance examination, Ethen Cole is framed and expelled from school, losing his chance to study at the Battle Pet Academy. Just as he feels despair, the Battle Pet System for battle pets activates.“Ding! The Blue Riolux has evolved into a Emerald eyed Riolux!”From then on, Ethen Cole begins his legendary career as a battle pet master.

Super soldier Su Chen, returned to the city and returned to the city, set off all directions! The king of soldiers that once famous the world, let everyone be convinced!

- Description from xbiquge

I can be the main character even though I’m not a hunter. Kang Moo-hyuk succeeded in all the raids with his genius and rose to the position of Strategic Team Leader despite not being a hunter.But one day, he got diagnosed with a terminal illness called “mana addiction”, and even got involved in a power struggle within the guild. With only a few days left to live, he decided to do everything he every wanted and set his passions ablaze. And he chose the tier 1 “Taesung Guild” to do so.But how can Kang Moo-hyuk grow the guild with Joo Se-ah when the rest of its members are amateurs?