A Hentai System in the World of Danmachi - Chapter 59 - 58 - I bought a mansion.

When an era came to an end, various forces set foot in cultivation to compete for immortality. A young boy who spent most of the time sleeping got lucky in the troubled times and became an unparalleled immortal who could cover the sky with a snap of fingers. Was he going to live forever?

- Description from Novelupdates

The World of Ephesus. A vast world plagued by Breaches containing countless Beasts of Corruption. A World on the brink of ruin as the Four Human Lineages defend the last bastions of Humanity! With the power of Gem Masters standing against the Beasts of Corruption, the flames of Humanity seek to burn ever brighter. In such a world, in the Mortal Branch of the Asmodeus Bloodline, Alexander awakens a Gem Socket that others consider defective. A Variant Gem Socket. Looked down upon by those who do not understand it, this supposed defect may just be the solution that the burning embers of humanity were waiting for. Follow Alexander as he entirely warps the perception of what a Gem Master is- as he embarks on a journey to become...The Empyreal Gem Master!

After all, transmigrators of this era were no simple matter. Some became slimes, others turned into treasure chest monsters, and some were even reduced to mere skull--such things were all commonplace.It was nothing more than playing a villain, Shiayar didn't care. Wasn't it only natural to pay some price to become stronger?[Destined Great Villain System][“Let this world feel the agony!”][Newcomer Mission: Let the young and naive Grand Duke's daughter of the Azure Garden Dukedom, Miss Silvia, experience the betrayal of her loved ones and, amidst the pain and despair, complete her transformation and rebirth.]

[You have been chosen as the new Lord.][You now hold dominion over your very own floating island.][Build your kingdom, summon legendary allies, and rule the worlds!][You have unlocked the SSS-rank Ultimate Gacha System.]Atlas Blackthorn was born with a miserable F-rank battle talent, certain he'd remain a background figure forever. But during a hunting trip, his teammate turned on him and hurled him into a deep ravine.That’s when the system chose him.Granted the Ultimate Gacha System, he gained the power to summon legendary warriors, rare artifacts, and, of course, waifus.With the system at his side and ambition burning within him, Atlas sets out to become the greatest Lord across all realms.How far will his dream take him?