Magus Reborn - Chapter 4. Debts and Stuff

The end of the world is coming, the world has undergone great changes, and everything has changed. Plants, animals, and even insects, as long as there are living things, have mutated.
Become more powerful, and even evolved supernatural abilities, such as chickens and ducks that can fly to the sky, such as cats and dogs that can breathe fire.
But only humans, without any obvious changes, seem to have fallen from the top of the food chain to the bottom of the food chain overnight.
Any creature that can open its mouth to eat can treat humans as food.
But fortunately, this world has not completely killed humans. Gradually, humans discovered that they had the ability to cultivate compatibility with other creatures.
As long as it has a high degree of compatibility with some powerful mutant creatures, it can be used for its own use to achieve the purpose of protecting itself.
Fang He is a person who is very compatible with mutant animals, but it is also because of his ability that he has changed from the strongest to the stupidest.
Fang He, who was reborn, said, “Hmph, this time…”

- Description from novelbuddy

Jun Xiaomo, notoriously known as “Lady Demoness”, finds herself chained and bound in a dungeon. Her hard-earned cultivation has been completely crippled, and she has no means of escape. Qin Shanshan, a lady she used to called her “close friend”, mocks Jun Xiaomo, revealing that Jun Xiaomo had been used by the people around her. Even her lover, Qin Lingyu was one of the masterminds scheming against her. Jun Xiaomo watches her life flash before her eyes and realizes that she had indeed blindly placed her trust in people. Her naivety had led to her current predicament.

Jun Xiaomo wanted to end it all. However, she is determined to deliver a swan song. Over the hundreds of days tormented in that very dungeon, Jun Xiaomo had painstakingly painted a complicated formation array with her own blood. With a determined look, Jun Xiaomo burns her life force to activate the array. Her sole intent? To bring with her as many schemers to the gates of hell as she could. The bright red light from thearray intensified, and the end was nigh.

…or was it? Jun Xiaomo opens her eyes and finds herself alive again; time had rewound right back to when she was sixteen years of age, albeit only at the eighth level of Qi Cultivation. Armed with the knowledge and memories of her previous lifetime, Jun Xiaomo is determined to learn from her mistakes and bring retribution to those who so deserve…

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

- Description from Novelupdates

As a corporate drone, Ashu was transported to another world, hoping to live a life free from societal pressures.However, he quickly found that even marrying a village girl would cost him half of his wealth!Fortunately, just when things were looking grim, his childhood sweetheart—who had trained for many years—arrived to fulfill their childhood marriage pact. Not only that, Ashu activated the Crit Refund System, which allowed him to earn rewards by binding with beings rated over 90 points![Binding with the Witch Childhood Sweetheart, 10x Refund on Magic Potion, Host Gains: Forbidden Water (S)][Binding with the Forest Elf, 10x Refund, Host Gains: Infinite Stamina and Infinite Recovery][Binding with the Demon Huntress Nun, 20x Refund, Host Gains: Demon Slayer Holy Crossbow (SS)][Binding with the Imperial Princess, 100x Refund, Host Gains: Sigh of the Heavenly Father Spear (SSS)]Ashu: “The refund multiplier increases as our relationship grows? I’ll definitely have to dive deeper into this!”