Jujutsu Kaisen: I Can Travel Back in Time - Chapter 17 - 11: There is no Kumamoto stop on the bus!

Before going to college, an ordinary high school student went to celebrate and got drunk. When he woke up, he found himself in a completely different world. There was a big sect, the approaching sect entrance examination, a slum where his body’s previous owner lived, and a shared memory about a missing young girl.

When he got tangled in a fight with a few punks in this different world, he fell off a cliff and miraculously found himself still alive, with two more voices ringing inside his head. They were Sword Master and Saber Master. In the company of them, he continued to find out more about this whole new world. He took the sect entrance examination, entered the sect, met a strange man in black, and even participated in a major competition of the sect to have a chance to win over his peers!
In this whole new world, he was born again and got to explore the fantastic martial world!

- Description from Novelupdates

“You call yourself a hero? After your greed killed my sister?”What would you do if all of your friends, everyone you ever loved besides your sister, died in front of you?What would you do if, because you were weak, everyone hated you and considered you a Wasted, someone who hurt humanity's chance to survive extinction?Adam continued fighting despite this abuse, because he still had 1 simple goal: even if he was nothing more than cannon fodder or wasted potential, he would keep his sister safe.But then, it wasn't the Kaiju or apocalypse that killed her. It was the Exalted, the strong, the heroes of society.The people he was supposed to praise were the ones who took his last hope in life away before killing Adam as well.So, when he regressed with a villain system that rewarded him for killing Exalted...[First Exalted killed!][Artifact: The Mantle has upgraded to level 2!]

After mistakenly contributing all of his attribute points to the drop rate, Xiao Shi found that every time he killed, he would get an item.

Slapping a mosquito to death, drop a pill.

Killing an evil spirit, drop a secret book.

Slashing a martial artist to death, drop the opponent’s cultivation tips.

….

When killing, Xiao Shi was shocked… “How did I become invincible?”