http://www.wizards.com/Magic/Magazine/Article.aspx?x=mtg/daily/arcana/1480

Assemble a mighty army of heroic Soldiers and Warriors, and power them up with spells that unlock their potential. Your opponent will be put to the test in combat by creatures that could become gigantic at a moment's notice.

The "Mortals of Myth" deck focuses on getting lots of creatures with the *heroic* ability on the battlefield and triggering that ability with spells with the *strive* mechanic, which allows you to pay extra mana to increase the number of targets the spell has. For example, you can use Ajani's Presence to give a single creature +1/+1 and indestructible, or you can wait until the late game and funnel all your mana into Ajani's Presence to give that bonus to multiple creatures. Skyspear Cavalry doesn't have a heroic ability, but flying and double strike make it well-suited to take advantage of this deck's power-pumping spells.