Hrm.
While I do think Death Knights being able to have a "ITS MORPHING TIME!" ability is a bit silly, I'm not particularly bothered by it. This is mostly because nearly 95% of all combat situations devolve into /roll fights, which are the merciless equalizer in the battlefield. In this situation, the armor-summoning is nothing more than a cosmetic perk; something flashy, but doesn't really affect how the combat situation goes. And, honestly? I'm all for flash. I love flash. Anyone who knows me knows that I favor flash and pizzazz and crazy over-the-top overly-detailed ridiculous bullshit over...everything. Why? 'Cause reality sucks, that's why!
That being said, there are those 5% instances of trust-fighting. And that's a whole different beast than anything else. When trust-fighting, its
assumed that the players engaging in that style
trust each other (hence the name!) enough for one to not god-mode over the other. This, of course, isn't always the case. Sometimes two strangers want to duke it out without wanting to deal with the hassle of rolls. And, that can lead to a huge problem when neither player wants to get defeated.
I think that's where this issue comes in, then. Because with trust fighting, you have to take in a LOT of different things into account. Fatigue, skill, situational ability, wounds, etc. Both players have to have a sense of humility and know when their character has reached their limit, with one of them emoting a defeat when it feels appropriate. Unfortunately, there can be situations where neither player wants to 'back down', believing that their character is da bestest fightar aroundz who shouldn't be defeated in this situation.
Then, I can see how the DK armor summoning ability could be over-powered. It effectively nullifies the element of surprise. It means that Death Knights can never be 'jumped' or caught off-guard, which is an advantage that no other class (besides maybe mage) has. So, I can see why people would want this ability taken away, especially considering how it has it's roots in Fandom rather than any solid lore.
Having said that, I think there is a larger issue affecting Death Knights. Well, perhaps not just any specific issue, but a multitude of them. For one thing, I think general society as of right now is too accepting of Death Knights. I see players of all types show virtually no reaction to the presence of a Death Knight, establishing relationships with them as if it was nothing.
Death Knights are walking weapons of mass destruction. They're abominations who fill the battlefield with terror and woe. I would think that any living creature should be terrified of them, and not want to have any sort of interaction with them whatsoever. I don't think any organization outside of the Ebon Blade would trust a DK in their ranks; what would happen if a DK lost their shit and turned on their allies? They should be viewed as a giant liability.
...and don't get me started on rogue Death Knights. Those things should be kill-on-sight by all factions (most specifically, the Ebon Blade).
What am I trying to get at? The perception of DK's should be much different than what they are. If your character was to engage in direct combat with one, they shouldn't expect the fight to be easy. They should know that the DK has access to abilities far beyond mortal comprehension, able to raise the dead and scorch the earth with rot and plague. In this sense, summoning armor and the like shouldn't be removed from possibility. That's what makes a Death Knight a Death Knight; they are living weapons of war and destruction. Their combat abilities should be above the average.
Now, should this make them invincible? Hell no! Anything can be killed, with the right amount of preparation and strategy. But when it comes to a Death Knight, the character should plan and strategize obsessively. Don't
just rely on the element of surprise; have the entire battle mapped out in incredible detail. In other words, the fight should look something like this.
Homura vs Walpurgis Night: (
Warning; spoilers for Magical Girl Madoka ahead though honestly if you haven't seen this by now you probably don't care.)
Lay on the offense thick and heavy. Have not just one weapon, but multiple weapons, prepared for all ranges. Have something to hit the enemy with no matter where it goes to. And even with all of that, be prepared for it
still not to be enough.
To use another example, take the mentality of one of the non-Jedi characters in the Star Wars universe has when they have to go up against a Jedi Knight or a Sith Lord. Can a non-Jedi kill a Force User? Yes, they can. But its not something they go on doing willy-nilly; they have to plan for it, meticulously.
So, now that I'm far off the original topic, I'll re-iterate.
In the grander schemes, the armor summoning stuff isn't all that big of a thing. I see other bigger things in regards to DK's and how they're played. I see a lot of people playing them "Wrong", but I never speak out against it (except now, of course) because I've given up on trying to change other people. Also, I think non-DK's need to have better reactions against them.
Also go watch Madoka.