In the MCU/Marvel with the Omnitrix/Ultimatrix - Chapter 25: The White Queen

Lin Wudao has traversed, and there is an invincible corpse collection system.

As long as you collect the corpses for the strong, you can get the things they owned or touched as rewards during their lifetime, and the obtained items are still strengthened.

Lowest, ten times stronger!

[You collected the corpse of the great emperor Jiang Taichu, and gained ten thousand years of cultivation! 】

[You collected the body of your fiancée Jiang Qingxue, obtained the Zichen Sword, a humane spirit weapon, and after strengthening it ten times, it was upgraded to become an extreme spirit weapon, the Xuantian Ancient Sword! 】

[You collected the bones of an immortal, obtained a ray of immortal origin, enhanced it by 100,000 times, and upgraded it to become the original origin of Hongmeng. After refining it, you can be promoted to the immortal emperor! 】

…

Since obtaining the invincible corpse collection system, Lin Wudao has embarked on an invincible road that can push through the ages and suppress the heavens.

- Description from novelbuddy

In the cruel world of Ranas, normal people are considered nothing more than trash. Blaze is also one of those trash. He and his mother has been treated like animals by his loser 'superhero' stepfather. But then everything changes when the SYSTEM gives Blaze a mission to kill him in exchange for superpower.Blaze does not hesitate.[Force Strike (E-rank) acquired][Force Strike has evolved into Force Impact (D-rank)][Force Impact (D-rank) has evolved...][Genesis Legion (S-rank) acquired][Genesis Legion (S-rank) has three Sub Powers...][You have acquired a new Equipment: Lantern of the Damned (Rare),...]The abusing stepfather who terrorizes his family.The bullies who made his life hell and sent him to the hospital, expelling him from the school.The despicable human-trafficking criminals who dares to kidnapp his friend.More and more people who do not deserve to live in Blaze's eyes.“I will kill them. I will kill them all.”But once Blaze has acquired more power. He now has the responsibility to decide what he should do with it.This world may be cruel and unfair but he shall be fair.Cruelty shall meet a cruel end.And the people who deserve to have a second chance shall receive forgiveness from Blaze.He is now the vengeful spirit in the night, rain down judgement on the corrupted that does not deserve their superhero title.

Leon was your typical guy, perceived as weak in his school because his skills hadn't awakened, even though they usually did at the coming of age. He attended the prestigious Milham's Magic Knight Academy, where snagging the top spot meant automatic entry into the esteemed position of a Magic Knight in the country. Unfortunately, Leon found himself in the lower caste, labeled the most useless student. To top it off, he was tossed into a class that served as a sanctuary for oddballs and delinquents. Yet, he couldn't care less, as becoming a Magic Knight wasn't his goal.Everything shifted when he crossed paths with Shredica, a woman hell-bent on becoming a Magic Knight at any cost. Observing Leon's lack of ambition and his apparent detachment from the academy's pursuits, Shredica saw an opportunity. She decided to exploit him as a pawn in her ascent through the academy's hierarchy.Yet, unbeknownst to Shredica, Leon was not the complacent, unremarkable figure she presumed him to be.

After the nuclear warfare, massacres started to spread throughout the entire world. The order between humans completely collapses, and the strong eats while the weak gets eaten becomes the #1 rule.