Well, judging by his brief dialogue at the end of the current Hildibrand questline, he seems he's searching for
the 'blade of light', which to me means he's obviously heard of the 'prophecy' from Louisoix's journal, which ironically was nothing but a metaphor for the player. So maybe I'm just reading too far into it, but it seems the reason he's beating up adventurers because he's misunderstood this metaphor for a real sword.
But I would be disappointed if there is an ilevel requirement for this (which it most probably would have) - it would restrict what is supposed to be a humorous sidestory to simply being connected to endgame stuff. But ah well, I guess we'll see.