Marked Ones: Advent of the Demon Prince - Chapter 339: Terror in the Dark [Part 1]

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

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.