Is It Really Impossible to Change?

When we fought against the Demon Lord in ancient times, we were already the strongest in the world today. When I used my last strength to seal the Demon Lord, the world returned to its previous peace. The world only remembers that the Demon Lord is dead, but no one remembers who defeated him. Now your eldest brother and third sister, will you still miss me? I'm gone. I don't want to become a useless person among you. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.