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

The "Pantheon's Power" deck is based around the constellation mechanic, an ability on enchantments that gives you a benefit every time an enchantment enters the battlefield under your control. Build up an array of constellation cards and watch their power amplify.

The more enchantments with constellation you control, the better each new enchantment becomes. If you control an Underworld Coinsmith when Grim Guardian enters the battlefield, your opponent will lose 1 life and you'll gain 1 life. While you control those, every enchantment you add to the battlefield will drain your opponent for 1 life in addition to its other effects. Add a Thoughtrender Lamia, and now your opponent must discard a card along with everything else.