'Wars have ever thus been won by information. Even in the far history of Ancient Terra, battles were decided by the side with the fastest messenger. The Ethnarch may spread his poison words throughout the sector, but little by little we fight back. Where we cannot strike with the bolter, we Librarians strike with disinformation. Vox-comms being miscommunicated. Orders to attack sites of nothingness. Encrypted messages being altered just enough so doom is brought on the recipient. This is our weapon. This is how wars are won'
Hetyrn Kylesa, Crimson Shrikes Librarius.
Librarians of the Crimson Shrikes are dedicated to a special type of psykic study, that of infomation alteration. Similar to the operations of the Vanus Assassin clade, any Librarian within a Shrike force will be deployed to attack the mind and morale of enemy forces, sowing deceit and error throughout the foe. This is done in a myriad of ways, but whereas the Vanus use their infocytic gifts, Shrike Librarians will instead use their minds. This can lead to Librarians staying in orbit when assaulting less developed or feral races, but in the case of the Shrine War, the Ethnarch deployed complex encryption software and codes. This lead to Librarians deploying from orbit and engaging in a shadow war, physically and mentally breaking both comms equipment and rebel messenger chains to ensure all enemy information lines were constructed of lies.
Below, we can see Epistolary Hetyrn Kyelsa deployed with Squad Alejandro of III Company. Working together, these Astartes fought in the shade, striking communcation lines and altering orders before blending back into the shadows. Imperial estimates suggest these types of actions would have lead to the Shrine War ending within an acceptable two Terran years. This, as we know , was unfortunately not the case due to Traitor Legion interference.