The death of Guthix in RuneScape.
First his whole home world and species gets wiped out thanks to gods using it as their battlefield, and he only survived by accidentally becoming a god himself. After it's clear that there's nothing left for him to do on his own home world, he leaves and travels the universe until he finds a perfect, untouched planet. He keeps it for himself and shapes it to be the way he'd like it, but eventually he decides to share it with others.
So he brings in species with no particular good/evil alignment or any concept of gods, in order to create a world where mortals could live in peace and balance without any gods. But eventually they start to worship him, and he realises how stupid he had been to believe they'd see him as an equal.
So he left them alone and went to sleep deep under the earth, hoping that they'd forget him while he was gone.
But then one day, thousands of years later, he's awakened by the very world screaming in pain.
And he finds that the world now looks like his old home world. War-torn and the people worshipping many different gods, himself included.
Being the strongest god, he easily throws out the rest of them and creates a magical barrier to keep them out, but he couldn't remove the memories from the people following those gods. His plan had failed, and the more he intervened, the worse it'd get.
He returned to sleep once more, knowing that there was nothing more that he could do.
And so, thousands of years from that, he's once again awakened. Someone has found his resting place.
Knowing full and well what they were planning, he allows the assassin to kill him without even trying to stop him...
Before dying, he tells the player the story of how he became a god, how all the years of living as something he hated has been tormenting him, and how he longs to see his family again. His final act before dying is to give some of his powers to the player, so that they can take up where he leaves off, and continue to protect the world from the gods without being a god themselves, in order to maintain the balance.
His final words were "Remember your purpose... Forget me..."
To make things even sadder, it's later revealed that ascending to godhood means giving up your right to an afterlife, so he never even got to be reunited with his family again after all... :'(
