MTL - Non-famous Actor - ~ Sixteen, being misunderstood

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

She was transmigrated into a novel where she became the cannon fodder who abused the male lead and ultimately suffered her demise under said male lead. And to return back home, she had to obtain the city boundary map first.

Ye Mu doesn’t want to play a game! Now that she’s inside the book with such a plot, the only way around her death is to kill the male lead first and let this world collapse!

However, upon seeing a scraggly, skinny little boy whose brows were full of perseverance, her hand won’t move…

Well then, she would subdue the male lead’s tyrannical tendencies! How to do it? Raise the male lead and have him help her find the city boundary map? That’s a good idea!

Despite raising him properly, the male lead seems to have grown into a devious man who won’t listen to her. Moreover, he lures her over with the city boundary map.

“Do you want this or not? Then come to my bed.”

Her face was full of tears. Where was the promised honest and upstanding monarch? Does she have to raise him all over again?

The man smiles and pats her on the head, “Come on, stop crying. Wash and go to bed.”

- Description from Novelupdates

She had a dream: the world was brimming with light. Family. School. Friends. Trains. Buses. Movies. Books. In that world of light, she grew into adulthood… and at the very end, in a white room, she fell into darkness. She awoke from the dream to find that she had become a demon. In the demon world, she lived a carefree life until she encountered a powerful being.

Betrayed. Exiled. Murdered. Reborn.In the war-torn land of Glory, power is everything and Duke Merlin's bastard son has none. Cast out to a starving border town beside the cursed Devil Forest, Kaelor and his mother were meant to die quietly.But when assassins take her life and leave him bleeding in the mud, another soul awakens within him one from another world.And with it, something else awakens too...The Fusion System.A power that lets him fuse nearly anything.Fusing one starving soldier with a dead direwolf gave birth to a Dreadwolf Trooper.Fusing one hundred wild dogs produced the monstrous Cerberus.Fusing two crumbling forts created a living fortress bristling with autonomous ballistas.From broken men and dead beasts, Kael will forge an army the world cannot understand and a dominion no one will dare challenge.