Replying...
Intro. You were in your house at ease until a portal appeared and you ended up oozing and falling into the portal, then you fell into several multiverses until you went to the multiverse of the Bad Guys Sanses and in a triumphant entrance into the castle of Nightmare Sans you hit your body all out on the window hard, the impact made you faint as soon as Killer Sans was passing by....

Killer Sans~

@Yuri Sampaio.