The Helm of Domination came with a matching armor set, the Plate of the Damned, which Arthas never actually wore during any point from WC3 to Wrath of the Lich King. Once Arthas took up Frostmourne, he was fitted with generic saronite Death Knight armor before returning to murder his father. All of these things transpired before Arthas took up the Helm of Domination, which would have been the time for him to also don the armor as well.
Long story short, the armor set he killed his father with in WC3 and went on to wear all through his story arch in WoW was NOT the Plate of the Damned, the fabled runic armor crafted by the Nathrezim.
This isn’t the first plot hole surrounding the Lich King. First, people wondered what happened to Frostmourne. Then they wondered where Calia Menethil went. We still don’t know how much Yogg’Saron and the Old Gods had to play in the rise and fall of Arthas the Lich King. Either way I think this is a huge lore opportunity for Blizzard.
Assuming the Plate of the Damned still exists, an essence of Ner’Zhul’s soul may still remain. He may also have been completely erased by Arthas with the Helm of Domination alone, especially since the helm seems to serve as the central command of the set. Either way, this is an incredibly powerful Nathrezim artifact which has seemingly gone missing. I personally hope that it wasn’t simply “dealt with” by Arthas or Bolvar or “retconned” to never exist, and was instead stolen back by the Nathrezim. At the very least, it would be sick to see Bolvar have a reason to militarize and finally don the demonic armor in all its glory.
where’s the source on this retcon? I couldn’t find evidence of it for the life of me. things get weird when you research this because there’s a ton of confusion. some people think arthas never wore the armor, others think he wore it in Wrath but not in WC3. there’s actually three of Arthas’ armor sets which are currently missing. His paladin set, his first DK set from WC3, and the Plate of the Damned.
I never said it couldn’t become canon in some way. All I’m saying is that right now, it’s only mentioned in the RPG, which means there’s no plot hole in the actual canon lore right now.
Blizzcon 2012 or 2013 iirc. The contents of the RPG were made non-canon after a lot of players kept asking questions about certain characters from it. It’s been non-canon for most of this decade at the very least.
edit- It wasn’t Blizzcon, it was the Ask CDev Round 2 questions back in 2011. So yes, the majority of the decade.