X!Tale is an AU created by Jakei95/Jael on Tumblr and Youtube. It has both a comic series and an animated series.
(Please feel free to add onto this!)
The animated series, however, is Non-Canon up to the point of Cross!Sans taking Classic Sans's soul. In the Animated series, X!Tale us shown to be an empty, white void. It was destroyed when Cross!Chara (X!Tale Chara) had killed everyone, except Cross!Sans (X!Tale Sans) and reset was impossible in a genocide route.
In the comic series, it takes place in the pacifist route, where Cross!Sans and X-Tale!Papyrus are Frisk's guardians up on the Surface, Frisk is the monster's ambassador, Asriel, Asgore and Toriel are still the royal family, Undyne is head of the Royal Guard, Gaster being the Head Royal Scientist. In the comic, everything but Golden Flowers are shown to Monochromatic of the color gray.
(Please only add things relating to Cross!Sans, Cross!Chara, or anything relating to X!Tale underneath each episode. Episode 1 of Underverse (0.1);
Episode 2 of Underverse (0.1);
Episode 3 of Underverse (0.1);
Episode 4 of Underverse (0.1);
Episode 5 of Underverse (0.1);
Episode 6 of Underverse (0.1);
Episode 7 of Underverse (0.2);
Episode 8 of Underverse (0.2);
Episode 9 of Underverse (Most Recent, 0.3);
Extra Scene (0.2)