World of Warcraft’s Sargeras was a strong titan whose role it was to resist evil and rid the Universe of demons. He believed that death was the only way to save the Universe, but the other titans weren’t pleased with this idea, refusing to help Sargeras fulfill his ideas. He actually releases the demons of Twisting Nether, releasing them out of Mardum prison.
Bringing about Chaos
The demons agree to serve Sargeras and Fel Energy became part of Sargeras’s consciousness. The Burning Legion is the name for the universe’s demonic forces under the leadership of Sargeras. The move from one world to the next looking to undo the creation of the Titans. In fact, the very goal of both Sargeras and The Burning Legion is to simply cause chaos in the world.
A War of Destruction
The Burning Crusade was a war started by titan Sargeras & carried out by his, what they call, legion of demons, known as the Burning Legion-. The whole purpose of it was to destroy all the life and to also conquer any worlds that may have existed. With all this happening it would rid the universe of any influences from the void lords.
The Imprisonment of Sargeras
The whole focus of the Legions was to go after the planet of Azeroth & many conflicts would take place over thousands of years. The attempts to target the planet however were stopped because those who job it was to defend the planet repelled the Crusade, resulting in Sargeras being imprisoned and the Burning Crusade coming to an end.