Toaru Majutsu no Index - Volume 14, Chapter 1: A Too-Quick Rate of Change. In_a_Long_Distance_Country.

By coincidence, Li Yunmu found a super machine from humanity’s age of darkness. From that point onwards, his ordinary life would never be the same! Aptitude? Innate talent? What are these? Could they be eaten?

I have neither aptitude nor innate skill, but my shadow can level up using hacks. Experience, Ability points, battle prowess… all of them could be hacked. Even while he is asleep or tired, he could still increase his skills.

- Description from Novelupdates

Mo Tianliao was a master weaponsmith and a demonic cultivator. When news spread that he was about to complete a divine weapon, cultivators from both the demonic and orthodox sides chased him down and killed him. In a stroke of luck, he managed to possess a new body and was reborn.

So what was the first thing on his mind after his rebirth? Avenging his death? Taking over the world?

Mo Tianliao: I have to find my cat!

—
Mo Tianliao: Why won’t you let me hug you? You used to be my cat!

Master: (unsheathes claws)

Mo Tianliao: Ahaha, this disciple has too much respect for Master, this disciple can’t bear to let Master walk on the ground!

Master: (lifts paw, sends disciple flying)

- Description from Novelupdates

Waking up from a hangover, Wang Hao finds himself reborn in an alternate world. To his delight, he realizes that he has a system to help him in this new world. However, his system turns out to be a highly unconventional one. Instead of serving justice and winning the respect of other people, Wang Hao has to do all kinds of bad things in order to make use of the system. So, Wang Hao embarks on the journey to being cursed for good…