Nightmare Sans

Nightmare Sans is the former main antagonist in the webcomic Dreamtale, he's the twin brother of Dream Sans who want to destroy him and everyone in his way who turn good in another comic called Shattered dream.

Story
At first Nightmare seem to be in good term with his brother allways playing with him and protect him, of course same if he's good the people of his town prefer Dream over him, he get bully everytime and every people call him "Evil" ,"Ugly" and "Monster" wich make Nightmare cry some people do feel compassion to him, but unfortunately sometime they agree with the people who despites him.

One day he finally get enough of being mistreated and decide to became like his brother, unfortunately while touch the golden apples from the tree it turn all black and he eat him despite the people trying t fight him for this, then he transform to a monster with tentacles and killed some of the people who bully him. Dream try to help came to his sense but Nightmare refuse and decide to fight after destroy their mother the Tree of Life, he also decide to destroy other universe who are AU such Underswamp Underfell and many other with Cross that he meet in "Underverse".

But he fail everytime to destroy the universe as in the finale Cross protect dream, In another Au called "Shattered Dream" He meet Dream who asked him to come see him as he did, he of course mocked him but when Dream show him the last apple who still dark, Dream then tell nightmare that he will eat it. Nightmare thought Dream was kidding but dream show him that he was not kidding and eat the apple as Nightmare watch in horror just like Dream did when he was transforming as his brother transform himself, Nightmare try to reason him but no avail Shattered Dream decide to go to all AU to destroy it as Nightmare was crying over the loss of his brother.