Basically, give me the name of two AUs (For example, Underfell and RevertTale), then say which one to double (Underfell Double and Revert Single) and I'll show you how they can combine in THREE DIFFERENT WAYS! (FellRevertRevert, UnderFell reverted to RevertTale, Revert!Sans but acts like Fell!Sans, RevertFellRevert, Revert!Sans that acts like RevertFell!Sans, and RevertRevertFell, RevertRevert!Sans that acts like Fell!Sans)