The difference is that we know Sargeras doesn't show his face around because he's not exactly easy to summon (the same more or less applied to Kil'jaeden and Archimonde as well). Azshara has no such excuses yet she definitely avoids direct confrontations of any sort.
Well, I remember quite clearly Deathwing growing in considerable size while unmistakenly trying to absorb the Dragon Soul's power in the WotA instance.IIRC it's just because he was so obsessed with it that he wore it on his body all the time.
I agree that the magical superblood may be Old God's own and exclusive material (especially if he developed such ability right in Cataclysm and not before, something I don't honestly remember) but Old Gods can't produce magma. Magma is, in fact, a natural element. It's molten earth in the first place. And that's strictly tied to Deathwing's original Titan gift. The Old Gods merely reshaped that basis.I know Deathwing isn't the most trustful narrator, but I kinda doubt Titans gave Neltharion the power to turn his wings and limbs into giant molten tentacles with enough power to kill another Aspect on their own. Same goes for magical superblood or the fact that nothing can kill him since he'll regenerate even from scraps. And I didn't mean they were replaced per se. Just that he got them and used them instead of the Aspect power for the most part.
Dark Shamanism is much more than simply bending the elements to one's will. It manages to corrupt and twist the elements. That's why Garrosh's shamans could turn the elements into "burned-out ash, corrupted waters and toxic air." Magma itself is considered a form of elemental unbalance as it merges fire and earth in a way it shouldn't be (at least within the instances where the elements are supposed to be independent and pure) and magma is definitely among the arsenal of Dark Shamans, seeing their ability to summon twisted molten giants and whose creation are considered a dangerous practice and threat towards elemental balance. Now, if we look at Deathwing, we see what once was the Aspect of Earth, who lorded over everything earth-related, turning into a fiery magma agglomeration. To me the parallel is obvious enough.And I'm not sure if the Void and Dark Shamanism is the best comparison. First of all, it's mostly achieved through Decay and only AU Orcs used Void for that. Secondly, Dark Shamanism, at least from what I gather, is more about a shortcut to what Shamanism can offer. Whereas in case of Deathwing, I'm not sure where the concept of shortcuts could even apply.
About Decay, well, Death and Decay can definitely be seen as the physical manifestation of Void within the universe much as Life and Spirit are of the Light. They're not directly related but when the primordial clash happened, it's quite easy to understand which one of the two cosmic forces had the bigger role in the creations of these physical energies. This is indeed further confirmed from the Warsong Orcs of AU Nagrand, that achieved very similar results to Dark Shamanism by harnessing the Void into their elemental practicies. The Old Gods are themselves, moreover, actual physical manifestations of the Void Lords within the universe, albeit their origin remain the Void realm, which means they may not actually unrelated to the Decay sphere.
Depends from the extent of that asset. Chances are that Azshara's own army was, back then, more valuable and strategically useful than Azshara herself.Well, as I said, she was most likely plan B. I mean, she's no Deathwing, but she still could have been a great asset for the Hour of Twilight and yet was almost unused by N'zoth.
Well, that if she's imagined as a literal back up plan, something that can't really be confirmed. I doubt she could even barely match Deathwing's immense destructive potential. Being a back up plan may also simply mean playing a more direct role in the grand scheme once Deathwing failed, ranging from working on freeing N'Zoth, resurrecting Deathwing himself or achieving the Hour of Twilight through other means. Then again, Deathwing actually failed and the Hour of Twilight never happened and she did nothing about it, one way or the other.And being a backup replacement for Deathwing would actually say quite a lot about her in terms of importance to N'zoth or her power, and rather positive things at that.