His Contractual Mistress - Chapter 3: His Moms Invitation

Wen Zhixing has transmigrated into the world of cultivation and has been unexpectedly abducted to the Wondrous Palace, where is full of infamous female cultivators. However, with his Immortality System, Wen Zhixing discovers that he could see their “Fortune Fragments” and take advantage of these Fragments by consuming his lifespan.[ Acquire the constitution: Revival of the Withered Tree.][Revival of the Withered Tree: Blazing Gold Quality. Can rejuvenate a withered body. Each time the body enters a withered state, it will undergo nirvana. After nine nirvanas, it will shed its mortal form.]...

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

“When everyone worked hard just to obtain pills, artifacts, wealth, or power. Well, hehe. All I need to do is buy them through the Invincible Exchange System!” Our protagonist said with a smirk on his face.

- Description from Novelupdates

Meet Sora and Shiro, a brother and sister who are loser shut-ins by normal standards. But these siblings don’t play by the rules of the “crappy game” that is average society. In the world of gaming, this genius pair reigns supreme, their invincible avatar so famous that it’s the stuff of urban legend. So when a young boy calling himself God summons the siblings to a fantastic alternate world where war is forbidden and all conflicts–even those involving national borders–are decided by the outcome of games, Sora and Shiro have pretty much hit the jackpot. But they soon learn that in this world, humanity, cornered and outnumbered by other species, survives within the confines of one city. Will Sora and Shiro, two failures at life, turn out to be the saviors of mankind? Let the games begin…