Sans

"'You're gonna have a bad time for what you did!' -Sans to Caillou Griffin"Sans is a skeleton that just wants revenge on those that wronged him and got away with it.

History
Sans' real name is Ness. He died while fighting Caillou Griffin.

An Epic Chat 3
Sans' adoptive brother, Papyrus, was erased from existence by Thanos in An Epic Chat 3. Ever since Thanos' defeat, Sans has never been the same, frequently going to McDonald's as some sort of coping mechanism.

An Epic Chat 6: Herobama Strikes Again
He was called on once more by The Elites to assist Caillou Griffin in Herobama's defeat. Sans killed both Herobama and Caillou Griffin as he feared the two were way too powerful. He then went to McDonald's to finish the Big Mac he left when he was called. Sans went to Grillby's afterward to speak with Dong Kong Luster.

An Epic Chat 7: Judgement Day
Sans and Cirno battle Goddle Dee, however, the fight was not in his favor. Sans prevented Judgement Day, but Pikmin Knuckles gave him one quick chop, killing Sans rather quick.

Trivia

 * Sans is the first main character to die.