Editing Scythes of the Emperor (section)

==Their Secret Shame==
Turns out that the reason why things went so badly for them at the hands of the Tyranids was because they’d let a Genestealer Cult infiltrate Sotha so badly that it ended up compromising their chapter serfs and, to some extent, the chapter itself. Their original gene-seed stocks tainted, their beloved planet and serfs either nommed or purged, and the original, non-Primaris part of the chapter reduced to about a dozen, the survivors decided to fade into history and let the Primaris take over the chapter name with a clean slate. Cawl allowed the remaining regular marines to make planetfall on their old home and die to kill the genestealer Patriarch that was responsible for their [[Dark Angels|secret shame]], thus allowing them some degree of final redemption.

With the Pharos (the secret of which the chapter was formed to protect) destroyed and all the old marines annihilated (along with their potentially tainted gene-stock), the new Scythes are basically a whole new Primaris chapter that just exists to guard a remote flank of Ultramar. But on the plus side, Cawl promised their old chapter master they would refit their space station and re-terraform the rockball that used to be their homeworld, which should only take a century or two.