Mahouka Koukou no Rettousei - Chapter 3Volume 26 -

Ye Kai was born with a weak body, spending his days with his mother and sister. on such a day he heard a ding voice and got Unlimited Item Shop System, where he can buy anything.The first thing Ye Kai buys from his Unlimited Item Shop System is Lust System, to make his fantasy true, where he is having sex with his mother and sisters.---The story is slow-paced so I will increase the pace from Dark Sky City Arc, so someone doesn't like slow paces then read it till the Dark Sky City ArcThird, if you think MC is beta then it's only in front of his mother, otherwise, he doesn't care about other people except for his family, and he is...pretty much ruthless towards the people.

A human warrior cultivating the Ancient Strengthening Technique has transcended dimensions and arrived on Kyushu. Together with twelve ravishing beauties with looks that were unmatched in their generation, will he be able to stand on the summit of this world?

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates

Sam Sanderson is envied by many for his job, however he himself didn't seem to like it much.

Due to his expertise in nanotechnology he was tasked with monitoring the state the Valkyries, humanity's strongest weapons who all just happen to be made into gorgeous females.

Forbidden from even touching any of them, Sam spends his days in agony watching flowers he couldn't hope to touch. However one day all of that seemed to change.