From their announcement:
None know of Guillaume le Pèlerin’s origins but all realise that to ask the man himself would be a quick way to an early grave, for his wrath is legendary and his sword sharp. All he will ever say is that he is a pilgrim, a wanderer looking for his own kind of peace and to be left to his own path. It is others that name him a vagrant knight, a warrior with no allegiance to any lord or land, a wildsman of Frankia with an obviously martial past, but the Merovingian court know nothing of him and no templar will admit to being his brother-in-arms.
So it is that Guillaume will descend upon the beast, the warrior and the demon alike without rhyme or reason, seemingly with no agenda or motive, but to the patricians and kingmakers Guillaume must be more than a wild card, cannot just be a simple chance occurrence that can change destinies, alter carefully-designed artifices with a single swipe of his sword; he must be a driven man, driven by another, one with designs of his own. This is why he is hated and feared, for he cannot be bought and he cannot be swayed, and all who try never return.