Knowledge: +806xp, Item: Spite Ale
In Mount Bloodhorn run to the southwest, pretty much as far as you can go. There's a PQ in the area, so if you see that you know you're in the right area. There's a named Spite there (Maegda), kill it for the unlock.
Also in the area of 54000, 28000 in Mount Bloodhorn there is one called Tarestil that you can kill for this. Note that he unlocks this even though he isn't a champion.