Originally Posted by Siirius Black

Spoiler Warining ***************

Well you have to understand that supposedly Glint and the Kunawang ( or however you spell that) are babies compared to the actual dragons. The Great Destroyer is a General of the actual dragon.

According to this article published in PCGAMER:

=====Dragons===========

"Never trust the past. There has been too much forgotten, too many things hidden beneath the sand of ages. Even your own memory can lie to you..."
—Decimus the Historian

Over the last 250 years, the races of Tyria have seen a great deal of strife and war. Conflicts between the humans and the Charr, the Norn and any who might challenge them, and among other sentient races have continually threatened the peace of the continent—but these are not the only issues. Although sentient races are one threat, there are, as always, wild creatures and monsters across the countryside; dangers to be faced and troubles to be conquered. But on Tyria, there are even worse things yet to be faced.

The cataclysms that tore apart the land and flooded Lion's Arch were not caused by natural forces, no more than were the earthquakes that freed the Destroyers in the northern Shiverpeaks. These were both caused by the surfacing of ancient powers—true dragons, more dangerous than anything Tyria has ever known before. Glint and Kuunavang were but youths, lesser powers to the ancients that came before. These mystic and terrifying creatures rival the gods themselves.

Primordus was the first of the ancient dragons to awaken, calling his servants from their slumber. With his breath, he twisted earth and stone, shaping creatures and giving them life. Although the death of the Great Destroyer, his most powerful general, set back the dragon's awakening by two generations, Primordus once again rose to create ever more minions far beneath the ground. To this day, he continues to spread his power throughout the deep caverns beneath Tyria.

After Primordus, the other great dragons began to stir one by one. The rise of the dragon beneath Orr caused the entire continent to surface, sparking a tidal wave that swept the coastline and drowned thousands. In the deepest waters of the sea, another dragon breathed, twisting the waters themselves into tentacled horrors that rose from every lake and river of the land. Only a few years ago, yet another dragon erupted from the northern mountains and flew south over the Charr territory of Ascalon. The land directly below the path of the dragon’s flight was corrupted, becoming a crater of horror. The ground blackened from the dragon's presence and any creatures caught within the wind of its breath twisted and changed.

Although these creatures are called dragons, they are as different from Kuunavang and Glint as night to day—more powerful, older, born of different, unfathomable magic, these horrors are controlled by no god nor any other power known to the races of Tyria. What connection they have to these "younger dragons" is unknown, but they certainly do not possess the mercy or familiarity with the sentient races of the world that Kuunavang or Glint portray. The cycle of their awakening reaches back to the time of the giganticus lupicus, and even further, back into prehistory. The only thing known about these monsters is that they have no pity, no curiosity—no concern at all for the other races of the world. Their only goal seems to be to dominate, to control, and to destroy.