Prime Dragons

The Prime Dragons are six powerful original dragons to exist. They are Alpha's son and grandchildren, Galakrond was created by Alpha directly and he sired the five younger Prime Dragons in that specific order: Malygos, Prime Dragon of Magic, Neltharion, Prime Dragon of Earth, Alexstraza, Prime Dragon of Life, Nozdormu, Prime Dragon of Time and Ysera, Prime Dragon of Nature.

History
When Alpha needed soldiers to protect the world, he created Galakrond, the latter sired five children who later mated with various dragons and became the parents of the five Dragonflights.

When Galakrond became mad, he was killed by his five children, they were rewarded by Alpha with grand powers. However, Ptog-Ogron, one of the Very Old Ones, corrupted Neltharion turning him into Deathwing, the Prime Dragon of Death.

Known Archangels

 * Galakrond: Galakrond is the oldest of the Dragons as well as the father of the Prime Dragons. He's the only Dragon created by Alpha, he's conceptless.
 * Malygos: Malygos is the oldest child of Galakrond and the Prime Dragon of Magic as well as the father of the Blue Dragonflight.
 * Neltharion: Neltharion is the secondborn of Galakrond' children, the father of the Black Dragonflight and the Prime Dragon of Earth, after his corruption, he became Deathwing, the Prime Dragon of Death.
 * Alexstraza: Alexstraza is the oldest daughter of the first Dragon and the mother of the Red Dragonflight as well as the Prime Dragon of Life.
 * Nozdormu: Nozdormu, being the fourth child of Galakrond, is the second youngest Prime Dragon, he's the Prime Dragon of Time, the father of the Bronze Dragonflight and the main force behind the Xelors.
 * Ysera: Galakrond's last daughter, Ysera is the Prime Dragon of Nature and the mother of the Green Dragonflight.

Powers and Abilities
The Prime Dragons were original dragons in existence, they are the strongest dragons in all of dragonkind, the six Prime Dragons, especially Neltharion and Galakrond are said to be stronger than Archangels and that only Diablo can match their level of strength.

Vulnerabilities
Unlike regular dragons, the Prime Dragons are hardly affected by basic draconic weaknesses such as dragon-killing swords. It requires Primordial Weaponry such as an Archangel Blade, Necro-Scythe, Archdemon Blade, or anything else on that level to harm or kill a Prime Dragon.