One of my favorite things to do is figure out if fictional worlds can know other stories as fictional or not.
FOR EXAMPLE, the Marvel universe CANNOT have Homestuck because Terezi is a clear reference to Daredevil, and people from the Marvel Universe cannot possibly know Daredevil is blind and uses a cane the rest of the time (unless maybe Deadpool ?)
Which of course means that it's probable that Undertale doesn't exist in the Marvel universe, or if it does then Deltarune will look pretty different because it's full of Homestuck references.













