SpyMaster16
You are from an... 'institution'... dedicated to turning humans into monsters. Since you, subject 1604BS, are a failed experiment, the institution uses you for whatever work related business they need. But one day you escape, running to Mt. Ebott, knowing they can't find you there. It is there where you fall, in more ways than one. Your long lost sister guides you to him, however she is telling you to make him more... murderous..
This is a Male!Frisk x Reader, but with a different twist...
I do not own Undertale/Its characters, I only own the writing in this book (and that includes all ideas too)