In Shadowlands we learned of Domination Magic, and how the User can subjugate others and compel them to do their bidding. The Primus and Zovaal also explained how the Helm of Domination & Frostmourne (armaments of Ner’zhul/Arthas) were tools of said Domination Magic, as was Kingsmourne (Shalamayne, sword of Varian/Anduin).
My question is: Why is it that Zovaal can use Domination to control everything (especially the living) but the weapons of Domination i.e. “Mourneblades” are seemingly only capable of Dominating the dead? If it had something to do with Domination being some kind of Death Magic or that Mourneblades can only influence the deceased, that’d fit with what we saw in W3: Frozen Throne & Wrath of the Lich King. However, seeing Zovaal utilize Domination Magic against us (who are very much still alive) caused me some confusion, and I’m having trouble trying to figure it out.
The impression I was given from the Primus/Zovaal is that Domination Magic can control pretty much everything in the cosmos, and we see that in some of the quests in Zereth Mortis, where we use the fragments of the Helm to dominate the local protoform fauna & automa, as well as weaken the automa and the Nathrezim in the N.Eastern sand pit. Zovaal even momentarily Dominated everyone atop Oribos at the end of the Sanctum of Domination raid. But, the Mourneblades are only ever used to subjugate Undead. Even Kingsmourne, crafted by Zovaal and his forgesmiths in Torghast, is only seen raising undead during the fight with Anduin.
I dunno if there’s a difference between “existing” and being “mortal”, but originally I thought that because we’re mortal and have “souls”, that would allow us to resist the Mourneblade’s influence. The automa, protoform fauna, and Nathrezim exist in the Shadowlands/Zereth Mortis, but they’re probably not “mortal” if we’re basing it off of having a soul. Same goes for the Brokers - not mortal, yet existing nonetheless.
Unfortunately, this theory falls apart due to the Helm of Domination eventually controlling Arthas, and Kingsmourne doing the same to Anduin; both of whom were alive at the time of being Dominated.
Thus, I’d like an explanation (or theory) as to why Mourneblades only affect the dead, yet Domination Helms/Magic apparently affects everything.