so uh, similarities :

-they both wear in blue

-they both are associated with some kind of blue

-they both have a special left eye

-sans and vriska (in her god tier) both teleport

-they both die by getting stabbed while not being ready for fight

-they kinda have the same laugh (hehehe)

-they both try to help the main character (john/frisk)

-they kinda wear the same outfits (a t-shirt, pants, something with long sleeves on t-shirt)

-they both make fun of the enemy before/after killing them (frisk in the spare betrayal/travos - vriska by making fun of tavros disabled legs/sans by making fun of you that you spared him by telling you to not come back because you and him are friends... bruh)

-they both know wtf is a timeline (altho all the trolls knew about it)

-at first they both hide their special looking eye (eyepatch/not showing it idk)

there are more but my brain is dead now lol

#undertale #homestuck #theory