Dream's End (185 cards, released November 2001): This set officially introduced the Weave and Kybar's Teeth regions, and included two preview cards for Bograth and Paradwyn. This set also saw the introduction of dual-region cards.
Dream's End begins to be where things get interesting, with dual region cards and the powerful Shadow Geyser spells. Core gets a huge power boost in this set and two new regions are introduced - Kybar's Teeth and Weave. Two more regions were previewed with a Hyren - Bograth and Paradwyn.