It is known that the Legions used Librarians before the Council of Nikaea. The I Legion, Dark Angels, had a Library as demonstrated by Librarian Brother Zahariel which most likely was disbanded. The III Legion, Emperor's Children, had almost no psykers and never maintained a powerful Librarium as the psyker ability came from a mutation which implied imperfection. The IV Legion, Iron Warriors, are not known to have any Librarians. The V Legion, White Scars, had talented and powerful Stormseers and were very similar to the Rune Priests of the Space Wolves. One of there own proposed the third alternative to the Council which was rejected initially but was later adopted after the Horus Heresy. The VI Legion, Space Wolves, had their Rune Priest and most likely they stopped using their powers after the edict but maintained their place as skalds for their Great Companies. The VII Legion, Imperial Fists, most likely had Librarians as there is a massive Librarium deep in the Phalanx. Given their position as the Defenders of Terra they most likely followed the Nikaea Edict and suspended psykic activities. The VIII Legion, Night Lords, Librarius was lead by former Chief Librarian Fel Zharost. First Captain Sevatarion was a powerful psyker as well. The IX Legion, Blood Angels, disbanded their Librarius as demonstrated by Brother Ecanus of the 202nd Company. The X Legion, Iron Hands, held fast to the Emperor's command regarding Librarians. The XII Legion, World Eaters, had psykers but ignored the ruling and declined to make more Librarians because of Angron's distain for them. The XIII Legion, Ultramarines, complied to the degree that Tylos Rubio was banished for using his ability to save his brothers. The XIV Legion, Death Guard, would not have had a Library because of their Primach's hatred of witchcraft. The XV Legion, Thousand Sons, obviously disregarded the ruling and carried on as before. The XVII Legion, Word Bearers, had a psyker name Garand who served in the Great Crusade and earned the rank of Warmaster. The XVIII Legion, Salamanders, had a Librarium led by Chief Librarian Lord Umojen who over saw its disbandment. The XIX Legion, Raven Guard, disbanded their library. Inachus Ptero, a survivor of Istvaan V was once a Librarian during the Great Crusade. The XX Legion, Alpha Legion, would neither confirm nor deign if they have them or in what numbers but did use them to help infiltrate the Raven Guard after Istvaan.