Join Date: Feb 2012
Location: Chattanooga, TN
As far as I can tell the only way to truly capture terra is attrition pure and simple. Horus was winning that battle due to isolating potential reinforcements until he decided he wanted a mono a mono duel with big E. I really only see Nids having the capacity for the scale of assault necessary to grind down the defenders. Chaos MIGHT have a similar chance but as mentioned the many regiments and chapters around the Imperium would be recalled. The Nid warp shadow right on top of the astronomican would make getting reinforcements very hard. Maybe chaos could stir up a storm or something but other than that I can't see another power really managing it. Or the Necrons could just make the sun explode, problem solved.