Spectral Syphons were machines that Erwin used in his attempted conquest of the spectral realm.
Nothing much is known about these machines, other then the fact that that they syphoned energy from the Spectral Realm into our realm. In one case, Erwin set up one in the Spectral Realm itself. The goal of these machines was to collide Pac-Land and the Spectral Realm together. Pac-Man eventually destroyed all of them, thus ending this evil plan after a showdown in Shadow Temple. Had Erwin succeeded by not being defeated by his own syphon, the universe would've become doomed to a matter destroying vortex that would dawn on the Earth & end the universe.