He was tall and slender in form and the head-case containing his soulstone was of golden colour. Khiraen was a close counselor of the great farseer of Ulthwé, Eldrad Ulthran, and accompanied him on the surface of the planet Tarsus to meet with the Primarch of the Emperor's Children, Fulgrim, and warn him of the betrayal of Horus. Khiraen, being mortally wounded in life by humans, insisted that their species were of no trust and urged Eldrad to kill them all. With Fulgrim throwing an enraged attack on Eldrad with his sword, as the Primarch was insulted by the implications of Eldrad concerning his brother Horus, Khiraen sprung into action parrying the blow for Eldrad and dueling Fulgrim himself. The battle was fierce and Khiraen managed to personally kill the entire contingent of the vaunted Phoenix Guard, as well as deliver a fierce blow on the Primarch's chest with his power fist. However, the Primarch was helped by the demonic properties of his Laeran blade and managed to cripple the wraithlord. Afterwards, still controlled by his blade, Fulgrim broke the golden sarcophagus that contained Khiraen's soulstone and delivered the soul of the ancient warrior to be devoured by the Great Enemy of the Eldar race, Slaanesh.