The Book of Regression, an item you get by vendoring an Orb of Scouring with 1x Scroll of Wisdom, apparently downlevels your character by 1 and resets all exp to 0.
What I want to understand is, for what reason would this be used for? The only obvious answer that comes to my mind is that certain PvP characters would want to be at a specific level threshold, and this would allow them to get to that threshold, but other than that I can't think of any realistic use for this.
Is there some intended use for this item?