Editing Chapter Sigma (section)

===Chapter History===
The origins of the Chapter Sigma are muddled in the chaos of the Heresy. Originally operating as a blackshield warband under the command of Warsmith Napha Sigma, the Chapter Sigma appeared condemned to die from attrition in their skirmishes against traitor forces until one day they were met by the Primarch [[Shakya Vardhana]] and his [[Eyes of the Emperor|Eyes]] in the wreckage of the traitor shipyards of Zenaal VI. 

Expecting to be purged due to their heretical origins, Warsmith Sigma and his warriors resigned themselves to annihiliation but were surprised by an invitation of peace instead. Napha Sigma himself was invited to speak with Primarch Vardhana alone and after three hours he emerged from the primarch's chambers and declared his support to the Eyes of the Emperor. On that matter, Shakya Vardhana acknowledged the Warband of Sigma as his honorary sons.

It is clear that Vardhana had forseen the eventual fate of the warband but his true intentions remain unknown to this day.
Together with the Eyes, the Warband of Sigma participated in the Siege of Terra as the defenders, losing much of their number at Eternity Wall spaceport. Warsmith Sigma himself faced the Lord of Change Sa'loxir'ath, who offered him the truth behind Vardhana's decision to preserve his warband. Upon Napha Sigma's refusal, Sa'loxir'ath promptly decapitated him.

Following the Siege, the survivors expected to be granted the Emperor's Mercy, but once again Shakya Vardhana intervened. What he shared with his brother primarch Gaspard Lumey remains undocumented and unknown, but following his meeting with Vardhana, his initial decision to exterminate the survivors was reversed. Ultimately after extensive tests for their purity, the Warband of Sigma would be allowed to continue as a chapter, albeit with certain caveats.

Their geneseed was deemed too tainted to be passed on to future generations, future marines of Chapter Sigma would carry the genetic legacy of an unknown loyalist legion instead. In response to that the 493 remaining members of the Warband of Sigma symbolically removed their Progenoids for destruction, a declaration that they would be forever free of their tainted gene-legacy. Today, certain agents of the Inquisition believe that the Primarch Vardhana foresaw a future where the Chapter Sigma would carry his genes and acted accordingly; others believe that he was merely acting to preserve a future where the Chapter Sigma served the Imperium.

Shakya Vardhana would have one last surprise for the Chapter Sigma, he informed them of a series of writings by Warsmith Napha Sigma, a secret project undertaken by the Warsmith following his first meeting with the primarch on Zenaal IV. These writings, the Codex Mathematika would form the foundation of the Chapter Sigma, doctrine where each battle-brother is equal and the chapter is greater than the sum of parts. Guided by the vaguest of hints by Vardhana, it took the Chapter Sigma over 100 standard years before they successfully compiled the Codex Mathematika.