[Brother Lucian]

Considering the happenings in the series, and the pow from Drakan, its steadilly been foreshadowed to come, due to his increasing unhappiness with the high lords. Especially when..

The Primarch Vulkan himself returns to Holy Terra, facing the High lords and citing he would rather kill them than working with them, but unity had to come first in this time of crisis. Drakan was twitching at the edge of his seat, hoping the legend would smite all the corrupt high lords, but then the moment passed and they were back to their old scheming.