MTL - I, The New Hokage of Konoha - Chapter 34 Subsequent impact

Due to an unexpected turn of events, Xia Fei consumed a Super Gene Optimization Fluid that bore no brand, expiry date, instructions or stated its place of origin.
Our story begins here…

In the end of the world, the fittest survive.

Come back from rebirth, seize the opportunity, just want to survive in the hopeless end times.

Three months before Mu Nan returned to the apocalypse, he sold all his savings to accumulate supplies, hoarded everything he could hoard like a hamster, and then huddled in his own house and lived a low-key life, carefully waiting for the apocalypse to come step by step…

- Description from Novelupdates

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

Dragon 5th is a powerful lord with incredible martial arts, and yet is wasting away from a fatal disease. The only medicine which can cure his sickness lies in the clutches of his venemous ex-wife, Madam Lovesickness, and is guarded by 7 dangerous killers, fugitives of the martial world. To retrieve the antidote, Dragon 5th hires Liu Changjie, a skilled martial artist who loves drinking and women, but has a mysterious past. All is not what it seems in this wuxia heist story.