Board Thread:Warhammer 40k General Discussion/@comment-4851119-20140118095944/@comment-24532429-20140211060006

That was my post above but I didn't sign in. About the lost legions being integrated with the Ultras, I think that would be hard to get away with unless they had never been united with their Primarch. In that case they could just be told that Guilliman was their dad and they would never know the difference. The problems would occur when after The Codex called for the breaking of the Legions into Chapters and individual Chapters were required to submit gene tithes to the Mechanicus. I doubt that the High Lords or The Inquisition would look kindly on a Chapter that was found to have unknown or expunged geneseed. And to add to my above statement: To destroy a Primarch would be a monumental thing. The Emperor allowed Angron and Kurze to live even though their methods and dispositions were unsavory to say the least. Only when he figured out that Kurze was a raving lunatic did he decide to do something about it, and we don't even know if he actually gave the order. He had no problem Sending Russ to dispose of the Lost Primarch so I don't see why he wouldn't do the same to the Night Lords. They only turned after Kurze told them to and was subsequently assassinated. Magnus was also going to be allowed to live even after he disobeyed his dad and mucked up the Golden Throne. Horus tricked Russ into destroying Prospero so that Magnus would turn. He knew they didn't get along so it was easy. So basically the only documented reason for the Emperor killing a Primarch is because he was a traitor.