I want a hero so good, so fierce and brave, they give everything and more to defeat the evil that looms over their beloved world. That´s their duty isn´t it? they won´t fail, and so, after a horrendous battle, they go back to bow to their king holding the evil king´s head as a gift.
However, there´s no glory received, quickly the hero discovers the consequences of their last battle were far greater than their did and nobody considers them anything but a calamity.
I want a hero that becomes a forgotten stray chased away by the very people they helped and I want the soul of the evil whose severed head rests buried under a tree as the hero promised the evil they would, to be reborn only to find out the hero that slayed them has become an outcast.
I want the just reborn evil to mock the hero for their charity and useless sacrifice for people who ended up turning their backs to them, the hero only listening to their mockery completely unamused before interrupting them when they talk about redoing their kingdom of terror with a sword pointed at them.
The fallen hero then tells the demon, they didn´t need people´s owe and wonder, but just wanted their safety and prosperity and if that meant they had to be cast away, they would be fine with it. However, they explain lowering down their sword, the world has prospered in the wrong ways and the hero´s battle with evil is the reason for that and as such, they have to fix it.
Having little strength and life left to live the hero makes a bow to make the evil he slained in the past, a suitable heir to a better kingdom that makes coexistance possible.
What could happen when buried anger and a newfound trust towards each other provoke a switch of roles while trying to protect such idealistic goals?