A Faustian Rubix is a menagerie of multiple things that if engaged within the wrong way have the effect not unlike being on the wrong end of a deal with the devil. It is also said to be a situation in which a person makes multiple incorrect assumptions or accusations of a person, which over time destroys their credibility and makes them a laughing stock. Attempting to solve a Faustian Rubix is a definition of such a situation.
Alternatively, it could also mean a creative wellspring of ideas that never seems to end, or with a perfectionist streak. Some of these ideas may have a dark undertone or sinister twist.
The author's mind was a Faustian Rubix of ideas..all manner, shape and size. When they finally got finished, the end result was sinister but satisfying.
They tried to label the man as an Adversary, as an evil alien, and as an employee of evil aliens. They tried to solve the Faustian Rubix and they lost what credibility they had remaining.