Hold On Mr.! Your Sweetheart is a Real Queen - Chapter 9: He said that he could die for her.

Poisoned by his wife, betrayed by his best friend, and abandoned by his children—Matthew died broken and alone. But when he wakes up thirty years in the past, trapped in his eighteen-year-old body, everything changes.Now, the halls feel haunted, memories from a future that may never come keep popping into his head, and something strange is growing inside him—something he can’t explain. Sadly, this second chance isn’t a blessing. It comes with a price.But this time, he won’t be the victim. This time, he’s the one in control.

The flicker and a lonely soul named Ye Zan came to the world that seeks immortality through civilization progress. He thought that he could enlighten everybody, but nowadays people are neglecting it.

The remnant soul even named itself “The lonely soul of Dao Zu’- but still could not find the body that was ready to incarnate it. “Well’ it thought, “ I still have technologies!”.

Do I need to master anything? SO EASY! I could just surf it on the internet.

Do I want to be a genius? SO EASY! I Just need to get some genes of genius.

Do I want to go around the world? SO EASY! I just need to launch my own satellite!

Everything is SO EASY here! -Alchemy, refining, magic symbols, different lifestyles- with the help of technology, they are SO EASY!

Technologies are not a panacea, but technologies can make life better, so Ye Zan decided to put down his roots in this weird place. Science and technology can strengthen the country, science and technology can also strengthen the spirit, Watch the journey of a lonely wandering soul under Ye Zan’s control and witness- what it takes to become a real master of science and technology.

- Description from Novelupdates

Oscar, a destitute young boy, died in a tragic accident and was reborn in the forgotten realm. As a member of the lowly Birch tribe, his solace comes from the fragments of a guardian's spirit, residing in his soul. After the decimation of his family in the hands of a powerful race known as the dreads, he embarked on the part of revenge, leading him to the path of transcendence.

Blayn transmigrates into the world of Akame ga Kill and obtains the Mangekyō Sharingan—Kamui! Not just one, but both Kamui!