This app is inspired by the mod FNF VS Skeleton Bros
The plot of this mod is Gaster starts a trial with BF for being the human with a comparable capacity to Frisk, and through his insight makes BF visits the universe of Undertale, and others more.
And in this app you can use the main characters of this mon Week1
Mod download: https://gamebanana.com/mods/356019 Since the character of this mod is too cool, I made it into an app