Oberdeii was a young Scout Marine who was originally a member of the Ultramarines Legion's 199th "Aegida" Company, which was assigned by the Primarch Roboute Guilliman to the world of Sotha as permanent protection. The assigned Astartes took pride in their duty and later adopted the crossed scythes symbol upon their pauldrons to symbolise those they protected, the scythe-wielding agriculturalists of Sotha. For over a standard century, the Astartes had carried out a ritual in which they cleared the area about the research site on Mount Pharos using a scythe. This simple rural tradition gave rise to the protection company's choice of icon.