"The Advocates, called the 'regrowers' in playtesting, revolve around cooperation. So it's only fitting that their art reflect that as well. Each Advocate has two main figures in its art: the Advocate itself in the foreground and a helper in the background. But did you notice that each Advocate illustration has one green and one white figure? For example, the Shieldmage Advocate himself is a Cleric, and his partner is a Druid. Spurnmage Advocate is a Nomad, and he's assisted by a Centaur. The idea is that you're forming a temporary alliance with someone else in order to get what you want, and since the Advocates only appear in green and white, the partnerships were made to match."
The above tidbit was taken directly from the Judgment Player's Guide found in the Judgment Fat Pack. The Player's Guide contains cool factoids about the set, some inside thoughts from R&D, plus a full-color spoiler of all the cards. In addition, you get a handful of booster packs, a novel, and a Spindown life counter. Good deal!