MTL - Mercenaries and Adventurers - v4 Chapter 143 , Carvin collar

Once a regular high school student, the protagonist gets sent to another world via truck. He reawakens to find himself contracted to a girl about the same age as him before passing, and that his body was no longer that of a human. Given a new name as the girl's contracted spirit, he spends his days at her side._ _ _ _ _ _ _ _ _ _ _This is not a novel I will be updating multiple days a week. The most likely outcome is me updating it once a week, but if any readers would like to read my other works, I would like to suggest reading the story I update most which is “Level One Isn't Weak!”.

“A cheat system? Do you take me for a fool? Nowadays, where can you find such a good thing falling into your lap? Scram from my head. Is this is new kind of fraud? Or is this a murderer training system of aliens that contains the ability of hypnotism?”

“No, I am the chaos that whispers from nothingness, the nightmare of all living beings in the Southern Ten Stars, the successor of the unparalleled God and… your elder sister.”

“…I only have a younger sister, I don’t have an elder sister!”

“No, you have one. I am an illegitimate daughter. It’s just that your dad didn’t inform you.”

- Description from Novelupdates

After dying prematurely from an incurable disease, Yuka Hikano finds himself in a mysterious realm filled with endless doors, each concealing divine gifts from powerful deities. He is not alone—others who have met the same fate of death stand beside him, unaware of the trials that await.They are put through various tests and eventually transmigrated into different worlds. But these worlds are nothing like the Earth they once knew.For Yuka, however, this apocalyptic world feels eerily familiar. It is a realm of endless war, devastation, and chaos—a world he once played in a game. Certainly not the kind of place one would wish to be reborn into.From infancy to adulthood, he must gather strength, knowledge, and allies to survive the horrors that lurk ahead. But when he awakens a system granting him a power beyond imagination, he soon realizes that blessings can also be curses.[You have gained Infinite Mana.]Infinite Mana...?What could possibly go wrong?

When a glowing portal yanks Leo from his struggling existence, he is saved by a mysterious system which gifts him new chance to break free from his side character experienceRebuilding an abandoned guild to honor his family’s legacy, Leo finds himself under the evil eyes of monsters, both from humanity and the gates he ventures intoin short : overpowered necromancer building a guild.