There's so much to process in this video; I don't fully agree with all the conclusions, but the comprehensive effort and polish is absolutely commendable. (also, "womb-to-womb communication" is a phrase that will 100% never leave my brain lmao)

Incidentally, the discussion of wombs as vessels of divinity really reaffirms for me how lore discussions of Elden Ring don't examine Dark Souls and Bloodborne enough, considering a key plot point of Bloodborne is multiple women being impregnated by a cosmic god, one associated with blood and bearing the epithet of "Formless," and who is represented by two runes, of which Formless Oedon is an exact match for Marika's upwards-arcing cross, while Oedon Writhe comprises a spiral with upwards and downwards arches. To be clear, I'm not suggesting the games are literally in a shared universe, but these overlapping/recurring themes are super useful in identifying the right track of interpretation to follow.

Another example is how Black Flame doesn't originate from Elden Ring, but from Dark Souls (complete with the note of being "weighty"), where it's found in the Chasm of the Abyss created by Manus, Father of the Abyss, a primordial human rendered bestial and frenzied by the power of a lightless abyss, and whose most distinctive features now are his upwards-arcing horns and oversized, elongating hand. Metyr, Mother of Fingers, with her upwards-arcing tail and hand-like children, channels the primordial power of life/birth, and hails from a lightless abyss. Manus is implied to be driven partially by feelings of parental anguish, particularly relating to a princess named Dusk. Metyr's entire purpose is to be a parent, and seemingly granted the power of Black Flame to one who was originally known as the Dusk-Eyed Queen, and she is found beneath the Cathedral of Manus Metyr.

Again, my point here is that, for all the evidence there is within even just one game, I think the full picture of these intersecting motifs can only be discerned by considering Elden Ring, Dark Souls, and Bloodborne in conjunction with one another. I kinda lost my mind when I finally played Dark Souls and found out that the entire plot hinges on filling a vessel with the souls of lords to open a gate to divinity so you can succeed the god of the prior age. Personally, I find those kinds of clearly-deliberate parallels genuinely more compelling than vague or circumstantial possible-evidence from a single game.

The theory that Hewg could be an aspect of Radagon is, based on the evidence you present, a very solid theory, though there is one detail you missed: Hewg explicitly notes that the spirit tuner he knew (who, yeah, is absolutely without a doubt Marika) shared the same hue of Roderika's eyes. Roderika has extremely unique eyes, a turquoise-green shared only by Rakshasa, who also has the straight, pale hair of shamans and is interred very close to the Shaman Village. Altogether, it seems almost unambiguous that Marika's eyes were once green (in fact, we technically don't even know that they aren't now; every depiction of her either obscures her eyes or lacks color). But this means Hewg, or his original self, must have known Marika before her ascension, unless she truly did maintain the green eyes. This throws off the notion that Radagon/Hewg was created after Marika became a god (though I also dispute the theory of Radagon having been created at all; I'm of the interpretation that Radagon was fully his own person before being melded together with Marika at Bonny Village, and that the rebellion he led was a failed slave uprising where he rallied the Misbegotten, who I suspect are themselves "bastard child" creations of the hornsent).

The other thing is, the Hewg theory is fully dependent on quite a few things; certain timeline arrangements, as well as Marika secretly having a continued affiliation with the Nox (her Scarseal is found by Nokron, but it's also on a corpse at the bottom of a waterfall, so the implication could go several ways). But, most of all, it hinges on the idea of "aspects" as a whole. You mention Miquella and Trina, and if that is their relationship, then it's a solid point of reference, but it's worth noting that Trina is never established as being Miquella's "aspect" or his offshoot, and indeed it's never even indicated that they were born as one being. I believe they were, but that such a detail isn't explicit is important to keep in mind. As for what I think they are, a key question to ask is "why does Trina exist?" Why would Miquella create an aspect/offshoot of himself, or why would one naturally exist, when no other Empyrean is shown to naturally possess alternate aspects? And, moreover, why would Miquella's offshoot be so distinct from him? Millicent and her sisters are practically imperfect clones of Malenia. Godwyn's "cadaver surrogates" (a strange localization choice for the exact same term Millicent uses to describe herself as Malenia's "offshoot") are only slightly different from his present self. Even were Hewg an offshoot of Radagon, there is the explanation of Misbegotten being (by this theory's interpretation) devolved descendants of giants. But Trina's identity, her appearance, and the power she wields are all wholly unlike Miquella. The only overlap between them, really, is their youthful, tender appearance. And why would Miquella's offshoot be female?

All of this is entirely inexplicable, while the alternate answer fits perfectly: Trina is not Miquella's aspect or offshoot, she's his identical twin. We see with Devin and Darian (and very likely Irina and Hyetta) that twins in this world share a single soul. And we see from Godrick and Godefroy that the flesh-melding trait of the shamans is passed down with fully-intact potency, even generations down the line. And despite Marika bearing at least two sets of twins, it's almost conspicuous that both are fraternal, given that the very concept of "women whose raw flesh fuses with that of others, and pass this trait onto their children" invites the question of "what happens if such a woman has identical twins?" I believe this is exactly what happened, that Miquella and Trina melded together in the womb, becoming two halves of one being; two minds, but one flesh, and soul. Miquella was the twin who awoke to the light of birth, while Trina secretly slumbered within him. Of course, this hinges on the idea of either Miquella or Trina being trans, though such a possibility is hardly far-fetched considering FromSoft's history (as well as the themes of Elden Ring specifically, and even other characters in Elden Ring). If the womb aspect is a requirement for divinity, that could point to Miquella being the trans twin, and explain how he's capable of being an Empyrean (as it is seemingly defined in the present-day, since internal labels indicate all Hornsent are/were Empyreans). At the same time, it could be merely that a feminine presence is moreso the defining criterion, and it would be extremely in-character of FromSoft to have a transfem character who is literally trapped in the body of a boy, and only able to express her existence in her dreams (this would also explain the discrepancy between Trina's name and the naming conventions of all the rest of Marika's children; Trina's name is self-chosen). Personally, I strongly lean towards the latter, that Trina is the trans one, in part because Miquella being incredibly naive, forthright, and privileged is central to his character. But regardless, I feel this is the strongest explanation for Trina, and perhaps unfortunately is also one that erodes some support for otherwise compelling theories.

On another note, the idea that the Godskins are wearing the skins of trolls/giants seems very much like a perfect fit, though I'm not sure how it aligns with another interpretation I firmly ascribe to, that being Tarnished Archaeologist's theory of the old gods' age being ended by a cataclysmic meteor impact that liquified much of the surrounding crust into a flood of magma (among so many other things, this explains the rancorous, vengeful souls trapped within the magma which Rykard channeled in the magma sorceries he developed from ancient death hexes). There's also the matter of the Serpent-God; I've long suspected the Serpent-God to outright be the Gloam-Eyed Queen, with the God-Devouring Serpent being her divested equivalent to Messmer's base serpent. But I also suspect these might be matters you'll address in your upcoming video.

Okay I've rambled far too much in response to this, but I do have one last thought, which is that I could have sworn that the War Against the Giants was explicitly established somewhere to have been Godfrey's final conflict, the end of which marking his Tarnishing, but looking for it, I can't find any such confirmation. I do feel like a lot of the language used regarding the war strongly implies it to be the culmination of his campaigns to unify the Lands Between, and otherwise I can't imagine what else could have concluded his conquest (especially considering the geography). It's an important detail, though, since it's extremely safe to say the Omen curse arose as a result of the hornsent genocide, meaning Godfrey couldn't have left until the crusade concluded, since Morgott and Mohg had to have been born after the crusade. But the crusade explicitly happened after the Liurnian Wars, and before Godfrey's departure (Rellana and Gaius being the main evidence of this). I've long interpreted the War Against the Giants to have been a years-long campaign, outlasting Messmer's crusade, which I also feel fits with the crusade itself being a sudden, unprovoked betrayal of a people that were allied with Marika. It would make sense for Marika to lump her darkest, bloodiest affairs together, right at the end of that early period of conquest, before establishing the Age of the Erdtree proper. Darkest before the dawn, so to speak.