You know a full picture of just 'why' and/or 'that' Rome is the center of Luciferian 'serpent' power on this earth which I fully believe just from the Biblical narrative that's pretty clear on the subject.
The idea that even though he's supernatural he still it seems requires or simply craves human involvement so there could very well be massive underground 'portals' (and tunnels) spread out across the world that converge on Rome. Is this part of the 'ley line' earth grid idea? I can't say the Bible refutes it. So it's just simply come to be where Satan's lair is so-to-speak and that's that.
Whom EVER he allows to join his circle and serve him in some capacity the head honchos live in the Vatican and work their craft out from there I'm quite sure.