10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Chapter 3, Part 6 Yuuji’s Imouto Sakura, Replying Email from Yuuji

The end of all worlds approaches.

The Demon King Order harvests lives from all manners of living beings.

Within this darkness full of despair,
A single person escaped from space-time, returned to before the world collapsed, determined to change the fate of the past.

But as time pass, he gradually finds out that the Apocalypse isn’t quite as simple as he thinks…

- Description from novelupdates

Ariadna Lereg Ilestri Pre Agrigent. And so my life begins with this ridiculously long name, born to royalty and the center of attention — all because of one dangerous man; the veritably insane tyrant king, ruthless conqueror of ten empires, nightmare of all continents… and my father?! Will I be able to survive this maniac?

At the end of the dark 40,000 years, the enemies in the Milky Way launched their final offensive. When the end of the Era comes, the eternal war will come to an end. The human empire has now reached its destined final moment.

But the gear of fate does not end. The fate of the Milky Way will be determined by him and them as it was ten thousand years ago. What will happen at the end of this dark 40,000 years?

- Description from novelbuddy