Here we come to the end of the scene with the first unclean spirit of Mark. So far as ghosts or transcendent spiritual hijacking goes, it was visually unremarkable. A lot of noise, signifying nothing. As a reference to the political situation at the time, it shows a powerful image. In that place and time, when the number and variety of schismatic groups has become a comedy trope, presenting a single person as having authority over any number of the violently conflicting groups would have been seen as similarly comic.
The first time it’s mentioned, the Greek phrase for “unclean spirit” is “πνεύματι ἀκαθάρτῳ”. Thereafter, this person is simply referenced as “ἀκαθάρτῳ” – “the unclean”. This word also means “impure” or “unatoned” in a Levitical context: something that hasn’t been approved by the high priests and given the mark of authority. While the Zealots violently opposed Roman rule, they weren’t exactly keen on the existing temple authorities, either, preferring a kind of populist union over tyranny. As such, the Pharisees who controlled the Temple wanted little to do with the Zealots, preferring to make deals with the Romans over conflict.
From this, it’s clear that the reference to “unclean spirit” specifically names the Zealots. We can look to future references to “unclean spirits”, “evil spirits” and “wild animals” to also indicate rebellious populations. After a year of civil war due to a clear breakdown of any official system to indicate successors, perhaps the dearest fantasy to any Roman at the time was a clear and obvious indicator of authority from the gods. They really wanted someone who could unite the legions and silence the grumbling hordes. Their idea of a “superman” was someone with inherent authority that everyone simply respected and obeyed.