Magic System in a Parallel World - Chapter 199 B-Rank Labyrinth

Going for a swim, she ends up in an ancient wild Beast World and ends up being brought home by a handsome wolf.

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.

This is a story about a legend, of one that can never be forgotten.
Summer, first time down the mountains in 16 years, after being raised by his 3 masters and Fairy sister.

‘Why won’t you follow the Rules of society?’ The rules are the tool made by the strong, so I follow my own rules.

‘Why won’t you just use your brain instead of your brawn?’ Idiot! Have you ever seen anyone use their brain, to get back at an ant that bites them!? No, they just casually step on it.

‘Oh, everyone says you’re a first-class beauty huh?’ well, I’m sorry but even you are not qualified to be my wife. Only a ‘Summer class beauty’ is worthy enough!

‘My enemy is sick?’ Oh, don’t worry, even if you’re on your last breath and I feel it’s beneath me to slap shot you dead. I’ll just fix you up and then beat you!

‘Who am I?’

“I am Summer in the spring, the autumn, and the winter, I’m the world’s first above the heavens!”

Follow me, Summer Day as I step by step become known as the world’s first master, the world’s first doctor, the world’s richest man…… a lot of other world’s number one, but most importantly, The worlds happiest man.

- Description from Novelupdates

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.