Thus the Demon King Stains the Night / A Tale of Return to Another World

I thought I, Yoinaka Yūya, had died after saving a girl from being hit by a truck... but for some reason, I had been reborn in a completely different world!? There, I honed my magical skills and set out with my sister to become a first-class adventurer. Looking back, so much happened. I was reborn in another world, my sister was killed, I succeeded in my revenge—— ——and was transported to the future. This is the story of a boy once called a hero in the past, who was sent to the future and now searches for meaning while fighting and struggling through life. (Both title and synopsis are tentative) Former title: The Second Coming of the Night Magician