EWoT:Coteren was an Asha'man in the Black Tower.
He was bulky, with black oily hair kept long and lose. He had a blunt face with pudgy cheeks.
Coteren was a full Asha'man in the Mazrim Taim's faction. He and some of Taim's men were leveling hillside with the One Power beside a group of Logain Ablar's men. Coteren caught Androl Genhald using a bow and then embarrassed him in front of everyone by showing how weak Androl is in the One Power. Logain's group became furious and everyone fills with saidin, just about leading to open battle between the two groups before Androl managed to calm them all down by making light of the situation. He also called Androl "pageboy". 
After Welyn was turned to the Shadow, Coteren told Androl that he had been demoted again to Soldier rank and so he removed abruptly the sword pin from the left side of his collar. This causes Androl to seize the Source, which Coteren then does as well, looking for an excuse to cause a confrontation. Androl manages to calm down and leaves.