Chapter 1: The strange visage at the end of the world

After the Pines Family saved Gravity Falls, the two uncle twins find a dimensional anomaly that may lead them to something stranger than Weirdmaggedon itself.
Meanwhile, a dark figure lurks the Town of Morioh, looking for the symbols on a wheel with the monster of one eye.

Gravity Falls x Diamond is Unbreakable Crossover because I'm nuts.