User blog comment:Legionaire22/Coolest Primarch/@comment-1507470-20121119174546/@comment-1507470-20121119212018

I'm not buying into it, but in Guillman's own words it would only ever be him or Horus... sanguinius was to etherial and Dorn too draconian, and guilliman had an empire, where as Horus was just a conqueror of worlds.