A portmanteau of the words Insect and Deus which means deity.
It is also a pun on the word Insidious which can be defined as stealthy , deceitful or intending to beguile. Seems like it fits the No Guard and Illusion abilities.
Personally I'm of the mind the shortlist contains way too many variants of "Moth" for its own good, crushing variety to shoehorn in an interpretation I can't really see. While our mon is an insect with wings, it's not really "mothlike" per se. Moths for example have two wings, this has six, and our wings are really stand-ins for legs to begin with, seeing as the CAP's main body has none. I leave it to your judgement if you want to do anything, but I think of the various "Moth" names my two favorites are Aurumoth and Mothereal. Biblically, the only important thing about Behemoth is its massive size, and I don't necessarily see CAP 4 as huge. Magna- just seems more about magnetism, which is usually electric, though it can be a portmanteau of Magnanimous, which does work. (Except a more blatant example of Magnanimoth has 11 chars so...)
I'm of course in my own corner here but after more research I still think a "Hex" name should be chosen since the Insecta Order is under the Subphylum Hexapoda, and the artwork does have six wings. "Ethereal" is a ghostly associated as "Hex" is if you're wary of that interpretation.
If I may make a small comment on this... Magna is a Latin adjective meaning "great". Magnus-a-um. Magna Carta. Great Charter. I don't think anyone using it in the name here is implying that CaP 4 has some magnetic element about it... If they were, I'd think they'd use magne- rather than magna to get that point across.
Also, regarding the use of "moth" in the name, I really don't think we need to be so anatomically correct when it comes to naming. It seems that people on here like to adhere to approximately the "normal" patterns of the games, but if you realize, there are a lot of instances in the Pokémon series where the Pokémon's name and its appearance don't exactly line up nicely. Think of Psyduck and Golduck. Psyduck is not a Psychic-type (despite learning a couple of Psychic-type moves) and Golduck isn't exactly gold either. Also look at Mothim. Four wings. Volcarona. Volcano + corona. Volcano is used here merely as an allusion to the Pokémon's Fire typing rather than its appearance (there's no sign of a volcano on its body. Neither can it learn Eruption, a word closely associated with volcanoes.) Similarily, the word "moth" in the names can merely be used as an allusion to the Bug typing. And I do think it resembles a moth-like insect.
Regarding its size, we can't really make an assumption here. KoA never gave a scale for his art submission so we don't know whether CaP 4 will be big or not. It's kind of a minor detail, and at this point I'm kind of nitpicking, but I don't think names that imply a large body structure should be disregarded just because bug is synonimous with small in size, and vice-versa. In fact, by choosing a name that implies a certain size to its body we can even get a general feel for those small details like height and weight that are usually decided towards the end, though that would be a poll jump in a way. In any case, that 600 BST certainly doesn't give me the image of a Butterfree-sized Pokémon.
Alright, so maybe it wasn't a small comment after all...
OK, I take that back. I have another submission to make. Veering slightly away from the moth concept: Larvicras (LAR' vi cras). It's a combination of mainly Larva (Bug) and cras (Psychic).
I decided to go with "Larvi-" rather than "Larva-" simply because "i" is more effective when it comes to combining words than "a" and because "larva" sounds more like "lava" to my ears. Same reason why Larvitar sounds better than Larvatar (which sounds like "avatar" to me).
"Cras" is a little more roundabout in capturing the Psychic essence of the name. Long story short, "cras" is Latin for "tomorrow". Tomorrow alludes to fortune-telling, an element commonly associated with psychic ability. Tomorrow is in the future, ergo fortune-telling. How's that for an obscure connection?
Also hidden within the name are the words "divinity" and "sacred", which mean basically the same thing and allude to KoA's art concept of a seraphic insect. "Divinity" is derived from "divine", which is found in the second syllable of the name and "sacred" is found in Latin within the word "cras", third syllable. The word in Latin for "sacred" is "sacra", so LarviCRAs. Those two references are more obscure than the whole "cras-equals-psychic" thing, but they're there.
Final Submissions: Divinimoth Larvicras
...my Latin studies keep mixing in my head and I'm pronouncing Divinimoth as Diwinimoth and Larvicras as Larwicras... Hahah. I don't even know if we're allowed to make two submissions. It's not specified within the guidelines and I really don't see a problem with it, so two it is.
I agree with bmb that 'Fly' containing names sound a bit unimpressive or insignificant. Glorifly would be a cute nickname for an Illumise though.
Aurumoth and Retriarch both sound grand, imposing and a little spiritual so I would vote for either of them! I love the bronze-silver-gold idea and the -arch suffix.
I also want to submit a name: Final Submission
The name is a 3-part portmanteau 'ala-ark-ael' with 'ala' reference alatus - the Latin for winged. Also 'ark' referring to arch which means leader/ruler/chief as in archangel or monarch. Also 'ael' from the names of the archangels Gabriel, Rafael, Samael etc, makes the name sound more biblical and ancient I think.
Edit: RavensNation I think you should change your submission to Divinoth - it flows better and keeps the clear 'divine' and 'moth' components.
Been trying to figure out a good name incorporating Imago, the final stage in the life cycle of moths and butterflies, but also the Latin word for image.
That comes out to 8 letters. I was tempted to go with gloria for the second word of the portmanteau, but that seems too common. Instead, I went with the Latin word for Victory, victoria.
Victoria seems fitting, given its legendary BST. The inclusion of Imago enables some trivia. If we choose to give it pre-evolutions, its name suggests it is the final in the line. But if we do not choose to give it pre-evolutions, its name can suggest it is the best bug there is.
There's probably no precedence even in real life, but hey, no one said it can't happen. And besides, Divinisect has been submitted now. It's basically the same thing, so I'd rather add a bit of variety.
Here's an idea: let's just say it's named a larva, but still functions as a full-fledged, 6-winged moth-like Pokémon. It's a smart Pokémon and never got rid of its coccoon upon evolving, choosing instead to transform it into the three pairs of "wings" that it can use as a sturdy, but breakable, armor.
Alright, I'm just reaching at this point, but the submission and idea are there, if anyone wants to give it consideration.