Worshipper – “Betrayal” [2nd campaign, 1st mission]

At the beginning of the mission, take the boots and a little further in the witch's hut, learn the Logistics skill (it seems to always be available there). Don't pay attention to the monsters, meaning don't attack them, but just collect the chests with experience that will be along the way. And fight the monsters from Inferno; they will join you.