http://japan-legend.com/wiki/index.php?title=Taga_Natsuki
The staff here keep the wiki pretty up to date. Plus, I've never seen Natsuki's religious belief stated at all. The only possible reference that can be referred to Christianity has been the mystery character of Apollon. But that when the Advocacy translated it to Apollyon (see here: http://en.wikipedia.org/wiki/Apollyon). Though with the current spelling that is used it refers to the Greek God of Apollo (http://en.wikipedia.org/wiki/Apollo).
That makes more sense since Greco/Roman Mythology has clearly been reference in the past. The Creators have been refer to as Uranus(http://en.wikipedia.org/wiki/Uranus_%28mythology%29), Archanfel's organization is named Chronos(http://en.wikipedia.org/wiki/Cronus), and Agito/Guyver III has reffered to himself as Zeus(http://en.wikipedia.org/wiki/Zeus).
I know this is a tangent of the current subject, but it bothered me that it seems you assumed that a person not liking someone for having a god complex is automatically a Christian. For me, that's the same as someone assuming you're amoral because you are raised Christian. Though, I'm sure you mean no harm, it just irks me that way.
Now I see the Guyver wiki has that listed, but Japan-Legend's wiki doesn't. I personally either look things up through the manga or Japan-Legend. I never look at other fan wikis because usually they just copy and paste what Guyver Advocacy posts. I just did a quick skim of Vol. 9 and saw nothing, so I'll have to check other volumes. If this is true, can someone post it so we can clear this up.
End rant.
Now on the actual topic. I'm very much anti-sparkles but I find no faults with your comparisons.