Let's say the quest map is divided in 12 Lands, one for each element (there was a cool map in vanilla forum, maybe we can use it?).
There are a bunch of quests in each zone, based on the element the zone belongs. The idea of the quests have the objectives of making the new players familiar with each element in an individual way, so there will have to be several quests that in certain way suggest you use a particular strategy. Designing the opponents and quests this can be done just with a 75% elemental filter. Defeating each opponent gives you a small reward, while clearing a Land gives you a much better playable option. What I have in mind is unlocking the 3x Mark in the Arenas. So, when making an Arena deck and want to put 3x Mark of Entropy and you didn't clear that element's Land a label appears saying "Clear the Land of Entropy to unlock 3x Mark!1one1!eleven!".
Quests don't have to be just defeating an opponent, but defeating them with certain conditions. They can be simple, just making them use a card like "have more than 20 purify counters in yourself (Oceanus)" or "your opponent must have quanta of every element (Discord)" or harder like "A random creature of yours will always have Gravity Pull. Finish the game with a creature with 100 or more HP"
A similar system can be done with Cardinal, Spiritual and Material.
Thoughts?