My theory relates to Shaidar Haran,my theory is that he is the DO. the evidence that I have is that is in ACOS when he is spying on Sammael and Graendal. 1.He can feel the difference in Saidin and Saidar, 2.He channels to burn a spear 3.He weakens if he is away from Shayul Ghol for any amount of time, he can leave on a limited basis, because some of the seals are broken and the rest weakened. 4.He is in charge of some of the forsaken.