The Incredible Adventures of Van Helsing III

Despite the achievement description saying "(Scenario only)" I was able to unlock this during story mode. Now, the easiest way to unlock it is to sell him a Set or Godlike item, then simply buy it back. The buy back price is the same as the sell price, so there's no loss whatsoever. The other half of this equation is actually getting a Set (green) or Godlike (purple) item in the first place. As I mentioned in "Million Gold Baby" the easiest solution is to buy Katarina's item set from the Xbox Store for a dollar. Then you can simply summon Pigazus from the summoning circle on the stairway to the right of the Command Post and sell him one of the pieces then buy it back to unlock the achievement.