Tigris Decon was the Chapter Master of the Ultramarines at the time of the Third Founding. Concerned that the Chapter would come under scrutiny from the High Lords of Terra, he sought to erase evidence that Roboute Guilliman had secretly maintained a phantom 11th 'Aegida' Company on Sotha. To this end, he send Chaplain Segas and Brother Wenlocke to deliver an offer to Captain Oberdeii, the last survivor of the Aegida Company. Decon offered him a choice between reassignment to the 5th Company for a chance to return to frontline duties, or taking one of the Ultramarines nine writs of succession to become Master of a new 'Aegida Chapter'. Oberdeii reluctantly chose to found a new Chapter, but chose to name them the Scythes of the Emperor.