The Myrddrall act as a sort of hive mind for the Trolloc and communicate through normal verbal communications with non Trolloc but the Trolloc they use a Magi control over them allowing them to control Trolloc in this hive mind way.
Their creation is from the crossbreeding of Human and Trolloc, and only results from less then 1% of these couplings. Since no human would couple with a Trolloc it becomes obvious what method is used. Despite this belief being true the true origins of the Myrddrall was through the experimentation of Tek who wanted to see what would happen if he mixed Trolloc and Humans together, and his experiment lead to what he believes is one of the more perfect races in the world. He had planned on making them the dominent race on the Earth through his menipulation but he eventually gave up on them due to the inability to increase their birthrate through any means except breeding them in isolation which he understood would never work in the real world.
See Also : Tek
Despite this belief being true the true origins of the Myrddrall was through the experimentation of Tek who wanted to see what would happen if he mixed Trolloc and Humans together. Tek during his experimentation believed that even though the humans were meant to win after the failure of the Arakhora he thought they lacked the mental fortitude to hold onto any kind of lasting victory which would allow them to grow into a world power. Because of this belief and a sick facination he begin experimenting on the Trolloc and the humans together as he believed that the single minded nature of the Trolloc would allow the weakenesses of the humans to be eraced.
War with the Elves
Myrddraal are genetically Trolloc offspring, but are throwbacks to their human origin; for some reason, throwbacks to the animal side of Trollocs' genetic heritage never survive. Their names, where known, are in the Trolloc tongue. One theory holds that Myrddraal are created by the channeling gene; this would also explain why they are needed for turning a channeler to the Dark One. They are believed to be sterile; no female specimen has ever been seen. For some reason, they are reported to lack a sense of humor by both Light and Dark. Myddraal do not have dreams. Their blood is acidic and will etch steel if not cleaned off; their fingernails are hard enough to scratch wood.
Myrddraal wear black armor with overlapping scales, and black cloaks which do not stir in the wind. They are able to move between, or disappear into, shadows, and mirrors only reflect a misty image of them.