MTL - America’s Big Hero - v2 Chapter 415 : It's me, Sean who lost!

A single distrustful phone call to the authorities led Ling Ke, who had crossed over to the eve of the Third Honkai Eruption, to endure years of torment as a lab rat.By now, the Crimson Herrscher had already “transcended,” Kiana was with Anti-Entropy, Mei was with World Serpent, and Bronya had long since reunited with Seele...As for Ling Ke, he had become the Herrscher of Dominance, commanding a thousand puppets.“From this moment on, I will exact my revenge upon this world!”The once ordinary Chinese man who had crossed over into this world, now completely consumed by darkness, revealed a terrifying, twisted grin.A forewarning—this is not a happy story.

It was one thing to have my hands and feet securely tied, but why was my mouth also sealed? I should at least have been ...It was one thing to have my hands and feet securely tied, but why was my mouth also sealed? I should at least have been able to make a noise! Why was I confined in a mental asylum? Why did it seem like everyone was afraid of me? Why... do I feel like laughing?----------------This is a story where Holmes and the Joker wreak havoc on the SCP Foundation. I hope everyone will enjoy it!

Xiao Chen, “the waste” of Xiao clan, had his engagement to the Young Lady of the Yang clan renounced.

And when he arrived at the sect that sympathized with him and took him in, he found corpses strewn all over the place and a mist of blood in the air. The sect was exterminated by a mysterious group that was looking for the ‘Wind Spirit Jade’.

He himself was left behind only half-dead for ‘wastes do not deserve to die by their hand’. Humiliated once more and on the verge of death, in the surroundings strangeness happened. A whirlpool sucked up the blood mist and diverted it into Xiao Chen’s forehead, transforming and enhancing his body.

- Description from Novelupdates

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.