Multiverse Returnee

Imagine for a moment you were summoned to another universe and asked to be their hero. you accept and eventually, summoned to another universe again. Which is the start of a million year journey home. Along the way you fight for what's right, ideals and to save the world. Even falling in love several times but it comes to naught. Having watched loved ones grow old and die. Eventually coming home? This is a tale of what happens after you get home.