* To know more, see:
About the AU
In this AU ,Swapfell is similar to Underfell , Except it has the characters of Underswap.
The characters in the AU behave like brats, they are mostly evil, they're usually yelling, and most,except for Papyrus and Temmie, are bullies.Papyrus is stil slightly like the rest, but has hidden motives.
As Swapfell is the Fell-ified version of Underswap, there are several changes with the characters. They also commonly wear red, since in Underfell, most character designs include the color red. The Underswap characters' personalities are the opposite. For example: Underswap Sans is kind and joyful, while Swapfell Sans is very arrogant and mean. Swapfell Papyrus is also loyal to Swapfell Sans, since he's 'His lord', while Swapfell Sans is very much like a brat. The characters behave like their Underswap counterparts, but with opposite personalities.