Tigurius has always stood apart from his Battle-Brothers. Even to the Company Captains of the Ultramarines, he is a figure of mystery, possessed of knowledge that goes beyond the towering datastacks and myriad weighty scrolls of the Chapter arcanium. Tigurius has recently turned his talents to divining the threat of the Tyranids. His predictions about their movements have been so accurate that it would appear he has tapped into the Tyranid Hive Mind - a feat that has driven lesser individuals quite mad.

If you thought Space Marine Librarians were powerful then you clearly haven't met Tigurius. As the Chief Librarian of the Ultramarines Chapter, Tigurius has access to every psychic power available in Codex Space Marines and, if that wasn't enough for you, he can use three of them every turn. Unless your opponent deals with him early on (which is easier said than done), Tigurius will rain hellfire down upon them turn after turn until there's nothing left. Well, nothing left in one piece at any rate...