The Veilwalker - Chapter 2: Alexander Gray

[You have become the master of the Warden Mansion.][Your first quest is to refine mana from one of your maids by having intercourse with her.]When nineteen-year-old Jett Talon suddenly wakes on an emperor-sized bed, he finds himself lord of a mysterious mansion where countless gorgeous maids stand ready to serve. His first companion is Mia, a blonde elven maid who checks his every box. After making love to her, Jett gains mana, unlocks legendary powers, learns his duties as Master of the Warden Mansion, and uncovers its hidden secrets.

The idiot Long Gen pretends to be a pig and eats a tiger, takes advantage of the girls in the village, travels across the countryside and forests, monopolizes the beauty and coquettishness, and achieves the legend of “Dragon Gen”. There is a widow in front of the door leaning on the door to watch, and a sister-in-law next door looking through the screen window… This book is determined to be a stallion, with the goal of pushing down and being pushed.

- Description from novelbuddy

Yuki, a high school junior, dies heroically saving a stranger and is reincarnated in a fantasy world, where he discovers an extraordinary and unrivaled power.

“What those edited and conceptualized main characters call ultimate and full power is but a grain of sand under the steps of my weakest subordinates.” Quote from Patrick.

Patrick, a regular arrogant kid with extremely attractive looks and a high IQ, lived in the alternate version of Earth. But in this alternate Earth, there were awakened humans who possessed abilities beyond the scope of human knowledge. Yet, despite living in an awakened world, Patrick didn't awaken any ability.

But just when he was annoyed with his unawakened life, he acquired an unknown entity called a system. With that, it opened a gateway of infinite possibilities that caused the existence of the story “GOD OF ALL SYSTEMS.”