MY.. M-MEMORIES!? (300 special)

evil sans undertable Before the human arrived in the Underground, Sans was a lazy and friendly skeleton who would often make bad jokes. He would spend a lot of time slacking off at Grillby's or sleeping at his sentry post, much to the annoyance of his brother, Papyrus, who hated laziness. Despite this, Sans was very caring about his brother, and they had a good relationship.

However, one day due to unknown circumstances, Sans starts to remember the resets. This changes him radically, making him kill other monsters just to increase his LV, not sparing even his own brother. After this, Sans stops being lazy and becomes obsessed with killing the human, doing whatever it takes to stop them. He enjoys the madness, cruelty and slaughter of it all. Sans still makes jokes, but he doesn't enjoy it as much as before. He frequently chatters with phantom!Papyrus, whom he still loves like a brother.