Really neat AU. They were thinking about Reverse Falls when creating this.
Creator: Buryooooo on DeviantArt
Basic Storyline: Dipper and Mabel go on the same adventures, except they FIGHT.
Characters:
Kill Cipher is the Alternate version of Bill Cipher in this AU.
Dipper and Mabel are stronger and great at throwing a punch, but still do their "nerdy" and "girly" stuff. They hate being called babies and will beat up anyone who calls them one. (For extra measure, Mabel helps Dipper out with the Laptop)
Otherwise, all the other characters are pretty much the same.