Blood elves = high elves? I’ll let these characters answer for me:
“We must put this misery behind us. We must enter a new chapter! And so I say to you that, as of this day, we are no longer high elves! In honor of the blood that was shed throughout this kingdom, in honor of the sacrifices of our brothers and sisters, our parents, and our children, in honor of Anasterian… as of this day we will take the name of our royal lineage! As of this day, we are sin’dorei! For Quel’Thalas! Hail to the sin’dorei!”
– Kael’thas Sunstrider, Blood of the Highborne
"As I suspected, it gets worse up ahead. The Silver Covenant is outright attacking innocent Sunreavers!
This cannot stand. While our prime directive is to rescue Aethas Sunreaver, we must also protect as many blood elves as we can."
– Rommath, Quest: Violence in the Arena
“It unsettles me to have to fight directly with the high elves of the Silver Covenant… but I never tire of slaying Alliance.”
– Rommath, Quest: The Kirin Tor’s True Colors
“Do you know how many elves—sin’dorei and quel’dorei alike—died to defend that land? How many continue to die? And you say I should just let it go? What the hell is wrong with you?”
– Lor’themar Theron, In the Shadow of the Sun
Baenan spat on the floor near the elf’s feet. “Ye blood elves wouldn’t know nobility if ye had th’ definition tattooed on yer foreheads. Pathetic, slavering magic addicts, ye even sold out yer own people!”
Talithar’s face whitened, giving Baenan the satisfaction of having hit a nerve. He realized it was unwise to bait his jailor, but he was too angry to care.
“Aye,” he pressed, “I’ve met high elves in me life. I know what ye did tae them. I come from Loch Modan; I’ve heard th’ stories from th’ Farstrider lass there—”
– Quest for Pandaria, Part 4, Link
“You think I do not know what I am? We sin’dorei were given a choice: our integrity or our well-being. As if that were any kind of choice at all. I chose my well-being. My wife chose her integrity.”
– Talithar Swiftwind, Quest for Pandaria, Part 4
One hundred years ago…
I and a small group of other High Elves traveled here from our homeland, Quel’thalas. We sought the ancient mysteries of Kel’thoril… to find why it was destroyed.
We found fragments in the ice, shards of the crystal. The Archmage we accompanied did not take long to fall under their sway. In our foolishness, we noticed too late.
His spirit wanders in the southeast, among those he drove to madness, still clutching the memory of the precious shard…
…
Maenius was a powerful mage and an honorable elf. His spirit did not deserve such an ignoble fate.
…
We were shocked before we died. Shocked that one among our noble and austere kind could descend into vicious obsession so quickly. We died as naive fools, the victims of our own blithe assumptions.
The living would know that these events would play out yet again… both here, and among the entire elven race with the fall of Quel’thalas.
…
Long after my death, my people would suffer an even greater mistake. The High Elves relied on the Sunwell and its glory. Never imagining a world without it, we would never make preparations to deal with such a fate.
Later, when the Sunwell fell to the forces of the undead, what was left of my descendants would be lost and helpless… and the path they would take in response would change them forever.
The Sin’dorei, still striving for redemption, would return here as well…
– Quel’dorei Spirit, Quest: Legacy of the High Elves and Quest: Descendents of the High Elves
We were not naive, as our forefathers were. We were suspicious and cunning and ready for betrayal at every turn.
Yet our pride and greed drove us to ruin once more. How many more will be lost to Kel’theril?
…
One year ago…
The legend of the Crystal of Zin-Malor reached Silvermoon, and I led a group of the finest warriors and scholars avaliable to this land. We brought ample mana crystals, so none of us would be tempted to taste the crystal itself.
The crystal did not need our hunger to ruin us. Once in our possession, it warped all but me into wretched beasts.
– Sin’dorei Spirit, Quest: Descendents of the High Elves and Quest: Pain of the Blood Elves
The opening of the Dark Portal brought news of my people’s fate. In a way, my exile shielded me from sharing in their downfall, but to see the Farstriders throw their lot in with Kael’thas…
I never imagined my one-time brethren capable of such a thing.
The homecoming I once dreamt of will never happen. This forest is the only home I have left.
– Theloria Shadecloak, (Link)
No, don’t feel bad. I get that a lot.
<Taela looks both amused and annoyed.>
I’m a HIGH elf, not a blood elf. Don’t worry, I’m not going to suck all of the magic out of you.
– Taela Everstride, (Link)
With those vessels and their power in hand, the scattered survivors of my people can resist the lure of demonic magic. Every quel’dorei we can save from our prince’s folly is one more that can help us regain our lost glory.
– Ros’eleth, (Quest: Vessels of Power)