MTL - My Inseparable House Guests - Chapter 3 Dark blood in the pericardial cavity

In a world fraught with innumerable dangers where living day by day is a struggle, a young man from the modern age transmigrated into such a world, accompanied by a peculiar system made for assassination.

There was no light in the night, save for the sound of war drums and war cries.

The young man listened carefully, it was the sound of his heartbeat and the flow of his blood.

What lay hidden in the darkness ahead? Is it man, god or……a monster?

There was no such thing as the best road, because the journey beneath one’s feet is limitless!

Transmigrated into the world of High School DxD, Roy believed he had been handed a life of luxury and glory. Born into the prestigious Lucifuge family, with his Sister Grayfia as his strict yet devoted older sister, he thought he was destined for greatness. 99,997… 99,998… 99,999… 100,000!!But... reality proved harsher: Roy lacked demonic talent and, despite years of training, remained a Low-Class Devil. his peers effortlessly achieve High-Class status, he’s been trapped in a cycle of endless sword practice and ridicule. Yet, he refused to accept mediocrity. Ten thousand sword swings a day, relentless training.. Until one day..[Ding! The Strongest Demon King System has been activated. Access functions to learn more.]---- High School DxD - Main World!1 - High School of the Dead [●] - First2 - Demon Slayer [●] - Second3 - Akame Ga Kill [●] - Third4 - Bladedance of Elementalers [●] - Fourth5 - Campione [●] - Fifth

An average man is reincarnated in the world of DxD! How do you survive in a world of battle-hungry monsters? With a cheat skill, of course! Devour the competition, becoming stronger with every fight! From the depths of the Familiar Forest, the Beast King will rise. (Harem, Gamer!SI)