Talk:Napstablook/@comment-100.35.46.125-20151012031740/@comment-220.245.123.90-20151012035751

If you kill all the enemies in the ruins before talking to him, he will fade out as you approach him and you will never talk to him during that run (you may be able to if you convert to a neutral route before reaching waterfall). If you haven't killed them all, you can fight him but at the end of the battle he will tell you that ghosts can't be killed and that he was only makibg his hp go down to make you feel better. Afterwards you will never encounter him in that run again.