Storyshift is an alternate universe that was created by Reddit/Tumblr user voltrathelively, AKA "Voltra".
It is a role-swap AU, unique for being one of the first to not swap personalities, and instead have the characters retain their canon personality while still being in a new role. It also started the popular "Pair shift" where characters swap in pairs based on their relations in Undertale. Papyrus and Sans are one example of a "Pair shift".This AU recently emerged from an indefinite hiatus, and is in the process of rebooting, as mentioned in a post by Voltra on the subreddit.
About the AU
As stated above, Storyshift is a role-swap AU designed on shifting characters in pairs, while still keeping their personalities and relationships intact. Right now, Storyshift is only on Shift One. Depending on Voltra's motivation, Storyshift might have multiple shifts. These shifts will have randomly decided pairs, and there will be up to nine of them.
The pairs included in Storyshift are as follows: Toriel and Asgore, Papyrus and Sans, Undyne and Alphys, Mettaton and Napstablook, and Asriel and Chara. The rest of the characters remain in their canon Undertale roles, unless the situation around them calls for them to adapt to a different role.
- The fallen humans' items are swapped around to different areas.
- The Worn Dagger and Heart Locket are replaced with the Prop Chainsaw and the Hair Clip.
- The six fallen humans now have names.
- Flowey is replaced with a new flower, named "Boogie." He is a lot more apathetic and quiet than Flowey.
- Papyrus is the caretaker of the RUINS. He came to the RUINS originally to scatter dust.
- Alphys hangs out around the RUINS, and wears a sheet over themselves. They are a lot more reclusive and shy than in normal Undertale for reasons not stated yet.
- Chara is the adoptive sibling of Asriel and the one you meet first in Snowdin. They keep their distaste for humanity from canon, but hold it back for you and for their brother, Asriel.
- Asriel is the adoptive brother of Chara. You first meet him in the middle of his LARP game with Chara, where Chara convinces him to let you play.
- Toriel is head of the Royal Guard, and estranged (but not divorced) wife of Asgore. She helps you throughout Waterfall, instead of fighting you.
- Asgore is the Royal Scientist, mentor and modifier of Undyne, and estranged (but not divorced) husband of Toriel.
- Undyne is the cyborg star of the Underground. She is the main antagonist of Hotland, chasing you down the entire way through, only to be interrupted by the help of Asgore, and worst of all, her manager.
- Sans is the lazy king of the Underground. He was a good friend of Napstablook and Mettacrit before they passed.
- Napstablook was a good cousin of Mettacrit before they died. Napstablook died from sadness after the loss of Mettacrit when they went to the Surface. Through unknown means, they became the flower known as Boogie.
- Mettaton, known as Mettacrit in Storyshift, narrates the game, and helped to carry out a plan to communicate with the surface.
- Burgerpants, as a result of Undyne's extreme training regimen, is now much more muscular. Due to an unfortunate accident with a shirt that was too small, he is now known by the name of "Bulgypecs."
- Reaper Bird has taken up a much more solidifed form, known as Corinthian. They are a boss exclusive to Storyshift, and fought in the CORE.
- Also worth nothing is that the rest of the Amalgamates, (save for "So Cold", or Snowdrake's Mother) have been released to the public to be with their families.
- The true name, Chara, has been replaced with "Shifty." The character Shifty has not been shown or hinted to as of yet, so their identity is unknown.