Malygos

Malygos is the Aspect of the blue dragonflight and one of the most ancient creatures living on Azeroth, and one of only a handful who were alive at the time the Titans departed. Norgannon, the Titan master-magician and keeper of lore, granted Malygos a portion of his vast power. From then on, Malygos would be known as the Spell-weaver, the guardian of magic and hidden arcanum. Malygos is a leviathan with small wings. His body is covered with crystalline scales of pure azure. His body shines with shifting colors that change constantly from blue to silver. Theoretically, since he and his children specialize in magic it is likely that their powers far exceed those of the other dragon flights since magic is the element they rule. Now that he has regained his sanity, he is once again taking an active role in the protection of the world.

With lucidity restored to him, there were some - particularly the red dragonflight, and even members of his own - who did not like where his mind was going.NotD 163 Believing that the spellcasters of the mortal races were responsible for all of Azeroth's troubles, Malygos began a terrible war to purge the world of "rogue" magic users, including the Kirin Tor of Dalaran. Realizing the situation had grown out of hand, Alexstrasza rallied the remaining dragonflights in the Wyrmrest Accord to combat Malygos' genocidal crusade. After much conflict around the Nexus, heroes entered Malygos' inner sanctum with the aid of the red dragonflight and defeated him, ending the war and depriving magic of its appointed guardian at a crucial turning point.