Thread:NapstablookInfinity/@comment-37421692-20181106015120/@comment-37421692-20181110035836

Dusttale is an Alternate Universe where, basically, Sans got pissed of that Chara kept killing everyone so he decided it would be better for him to just kill all the monsters himself so he can get EXP and kill Chara. For a way better explanation than mine, please refer to the Undertale AU Wikia (not the regular Undertale wikia).