Nightmare is a god. Not only is he a god but a king as well. A fair and just king at that.
Despite being the most feared being in the multiverse he is surprisingly the opposite of what most would believe. They believe he is a cruel tyrant when the king is actually rather caring.
The only problem with the king is that he doesn't have a heir, not like he would need one. That would soon change however, all thanks to a goddess.
The Goddess of Fate.
(TW: unaliving thoughts and memories at the beginning. It gets better over time, don't worry! Trauma is difficult to overcome...)
You didn't want a second chance.
You didn't want to survive.
You wanted the sweet release of death.
But it seemed like the universe was far too cruel to allow you even that.
It took away your memories, your free will to choose whether you live or die...hell, it took the one thing in life you owned! Your own name!
And now it seemed like you had to live yet another cruel life, doing things you never wanted done to others. But...at least you could do things your way.
Maybe this second chance wouldn't be so bad...
(Reincarnated as Nightmare Sans, but unlike other stories, you have no clue what Undertale even is)