Reincarnated as a demon inside a dungeon - Chapter 115

Mu Zhiyan, after being transmigrated a millennium (1000 yrs) into the future, discovered that he was raised by his adoptive parents as a tool for them to access the heritage his (dead) biological parents left behind. When he was at a loss for what to do next, he discovered that his body hosted an additional
pharmaceutical system.

For a chance to return to his era of Earth, Mu Zhiyan decided to practice and practice; he must train the system to full level as soon as possible.

However, reality gave him a slap in the face. The world is dangerous and dreadful, making Mu Zhiyan recall his mother’s words of holding a thick thigh, resulting in him locking his eyes on a cool general…

So the rumored mysterious Mu Master faced General Han with a serious face: “I allow you to follow me, General Han.”

General Han: “…”

- Description from Novelupdates

In the wake of the apocalypse, betrayal doesn't just stab you in the back—it bites. Zorvax learned this the hard way. Abandoned by those he trusted, he didn't just become another number in the legion of the undead. No, his fate was far more peculiar.“I thought death was the end... I was wrong,” Zorvax mutters, his voice a gravelly echo of his former self. He's a zombie, but with a twist—he's got his human mind intact. Trapped in a decaying body with an insatiable hunger, Zorvax finds himself in a gruesome predicament that's just the beginning of his ordeal.Enter the 'Zombolution System,' a mysterious power he awakens that's as cryptic as it is potent. “They wanted a monster? I'll show them the true meaning of terror,”Zorvax boasts, with a smirk only a sentient zombie could muster. This dark gift is his ticket to ascend beyond a mere walking corpse, promising to unlock abilities that could crown him the emperor of the undead.As Zorvax hones his newfound skills, the line between man and monster blurs. Will his human intellect triumph, or will the beast within claim the throne? “This world has no place for the weak,” he arrogantly declares, ready to challenge fate itself.

I had a supporting role in a modern fantasy.

The loyal dog of a villain with an angel’s name, Cheon Sa-yeon, and an unfortunate supporting character who died on his behalf, Han Yi-gyeol.

In order to escape from Cheon Sa-yeon and survive, he must use the protagonist, Ha Tae-heon.

But Ha Tae-heon, who he thought of as a lifeline, was infinitely indifferent to him. Rather, Cheon Sa-yeon showed interest.

But besides that, something strange happened.

The events that occurred in the original story had advanced, and the gate and monster levels had risen. Even the people were “different” from the original.

The original version I was trying to use was wrong.