Board Thread:Warhammer 40k General Discussion/@comment-27561619-20160128225202/@comment-27561619-20160130205224

One of Abaddon's Chosen is the Lord Deceiver Ygethmor, a powerful Chaos Sorcerer and it is hinted that he may have been a Librarian of the Sons of Horus but there is no literature confirming this or that the XVI Legion had a Librarius but given Horus' proclivity for absorbing valid tactics I can't see why he wouldn't utilize that asset.