I already asked this dumb question in one of my discords but it is my duty to subjugate the forums to my nonsense but seriously??? Is he like the Thing from Fantastic 4 but also undead? An undead rock man!?!? Why is he made of rock? Is it because his armour melted into him?
What is the deal with Bolvar?
I accept both serious and dumb answers.
He is ice.
But also fire.
That’s how you know he is very important.
At the end of the Wrath Gate, Alexstrazsa and her pals went in to purify the plague that was unleashed on the armies of the Scourge, Horde, and Alliance. They did this by lighting everything on fire. Bolvar was in that fire and it burned him horribly.
Not sure why he survived. Could be the lifegiving properties of the Red Dragonflight, could be the Light preserved him, could be the Lich King kept him alive. I don’t remember the exact reason. Either way, he ended up charred and fiery. His flesh is just really blacked and ashy now.
So I guess when they Lich King’d him, his affinity for fire made him a 
fire Lich King . It’s sort of like how Ner’zhul is his rookie form, Arthas is his champion form and now he’s in his ultimate form, Fire Lich King.
Kinda a shame, I think icy blue was a good look. We have so many fire themed villains. Need some icy bois.
Yeah, I think his thing is that he’s like… perpetually dying and forever lit by the Red Dragonflight dragonfire, which seems appropriately horrendous
He’s more of a charcoal man.
BBQ Boi — charred on the outside, morally grey on the inside.
He is badly burned undead corpse that is somehow still burning, like Stratholme.
Purged the blight at least???
If we get a blight themed Lich King we’ll have a Lich King color for every DK spec!
Arthas - Frost
Bolvar - Blood
Sylvanas? - Unholy
The real answer- he’s not made of rock, it’s charred flesh and ever-burning fire. He was preserved by the flames of red dragons, infused with life, while in a state of death. He’s in constant agony due to the polar forces inside him. He’s not undead, but he’s also not alive. The dragons halted him somewhere between, and that’s where he’s doomed to stay. It’s quite sad actually.
He is undead. He says as much in the Death Knight order hall campaign.
Bolvar himself never died. The Lich King is a separate entity comprised of the minds of several people. Two of whom are undead.
Intriguingly, necromancy seems to render one effectively undead over time. Supposedly Arthas was eventually undead, despite never officially dying. He was certainly able to cut out his own heart and not die.
I’d say that by now, Bolvar is more or less physically undead.
I wouldn’t be so sure it works the same way for him. His physical body is infused with the fire of the red dragons. The essence of life itself. I’m not sure he’d still look like he does if he were undead.
This is true, he’s a literal hot mess. Death and life mixed together. With fire. And a daughter somewhere who thinks he’s some dead hero.
Bolvar is the hottest of hot messes in every literal and figurative sense.
Bolvar is most definitely dead. Even if the Red Dragonflight’s flame didn’t render him dead-dead, he was still mostly dead when Arthas got his hands on him and proceded to torture him. And Arthas wasn’t one to spare the rod.
Bolvar remarks the Dragon’s flame kept him functioning, but as that was literally the only thing keeping him going I think he’s close enough to classify as undead.
Which means we now have three different forms of necomancy. The Legion/Scourge kind. The Lightforged Kind. And the Dragon Flame kind.
As of now, he’s listed canonically as human, not undead?
Still, we don’t really know either way. It would be interesting to have it come into play though. The fact that the current Lich King is infused with life.
Maybe Bolvar is like the flaming zombies in Resident Evil? I hate those guys!
I guess we can spin a wheel and wherever it lands will be the next undead type??
Bolvar is dead dead.
He died to the blight, then the “Dragons flame, sealed my fate. The realm of the living, can no longer comfort me.” Basically just set on fire and his armor melted onto his body. He was probably still on fire when Arthas raised him. And Arthas probably thought itd be funny to make him undead, still burning with fire from the Life Aspect.
Oh Arthas and his jokes
I think this is where 2nd generation death knights come into play, where they are slowly corrupted and have their souls drained by their runeblades. With the loss of their souls, they essentially become undead. Arthas was basically the first of these.
Then again, necromancers and acolytes were considered undead in WC3 so… maybe I’m mixing up old retconned lore with headcanon.