This is the after math of Undertale pacifist 

You are frisk and you are in the underground but Chara is there making you choose decisions you don’t wanna make it

*Sans is just chilling until underplayer arrives*

You are Chara you enter the judgement room to encounter sans looking at you he is the weakest monster in the underground so you don’t take him that seriously which was a mistake

*You are Chara and you respawn at the start looking at sans across the judgment hall ready to fight him again*