Despite the top-down nature of its design in order to serve the setting of an ancient-Greece-inspired plane, Theros block is still technically the long-awaited "enchantment block." That theme didn't come through as strongly as expected in the first set, but Born of the Gods is already known to have a keyword mechanic that revolves around enchantments. The field is wide open for what that could be, but some of the options are right out:
- Enchantment lands. The divine creations in Theros have included such unusual type combinations as enchantment artifacts and enchantment creatures, but according to Mark Rosewater, the debacle of artifact lands in Mirrodin block has made R&D skittish about experimenting with enchantment lands, affinity or no affinity. And in case you weren't around during that block - Yes, it was that bad.
- World enchantments. The world type is an odd duck among supertypes - a sort of greater-than-legendary that precluded more than one world permanent at all from being on the battlefield at one time, with the new ones causing the old to go to their owners' graveyards, it sort of doesn't work unless there are a decent handful of enchantments with the supertype. While flavorful, they sort of step on the toes of Planechase planes, and according to Mark Rosewater the possibilities for future world enchantments are very slim.
- Tricolor gods. We know the Theros Five will be followed up by five more, multicolor, gods in both of the last two sets of the block - but they were always meant to be two colors each. Following up a Ravnica block with tricolor iconic legendary creatures, as cool as they may have been, makes bad inter-block synergy sense.