By now everyone in the Magic rumor community has their own theories about the minor gods of Born of the Gods and Journey into Nyx, the ten-card extension of the cycle we all know from Theros. I have already dealt with the enemy-color gods - or rather, three of them, Iroas the god of honor for red and white, Kruphix of time for green and blue, and Pharika of healing and disease for black and green. Now seems an appropriate time to turn my attention to one of the allied-color gods: Specifically, Ephara, the presumed white and blue god, who is significant in the history of the polis of Meletis.
Ephara's main mention in the lore has her as the main player in the early history of Meletis. The story goes that once upon a time in the distant past, Meletians were enslaved by an evil Archon, Agnomakhos, and his Leonin servants. Ephara gave humanity the gift of spellcasting in order that they might overcome the tyranny, and when they succeeded, they banished the Leonin to the wilds. Since Ephara is seemingly the god of wisdom and has a city she holds in especial favor, she's essentially analogous to the Greek Athena, who lent her name and her guardianship to Athens, the city-state on which Meletis is based.
As far as her mechanics go, Ephara is probably excellent at enchantment and artifact crafting, as Purphoros is, but without his destructive side. She may also have lifegain and card draw elements to represent peaceful progress.
The only mention Ephara gets in the name and flavor texts of Theros cards is on Ephara's Warden, whose flavor text underscores just how close the relationship between Meletis and Ephara is:
"When you threaten the sanctity of the polis, you insult Ephara herself. If she doesn't smite you, I will."
Unfortunately, the art of that card doesn't have the same sorts of clues that many of the other god-related cards in Theros do; there's no statue in the background that seems to represent Ephara, though there are plenty of works of art. Ephara's Warden is guarding a treasury, because Ephara is also the god of artifice and handicrafts - more to the point, she represents everything having to do with "civilized" pursuits.
As far as her relationships with the other members of the pantheon, they're not hard to guess. She's probably the best of companions with Heliod and Karametra, as justice and agriculture are part of the underpinnings of civilization. She seems to have a mutual respect with Iroas - warfare ought to be the last resort of a cultured people, but Iroas fights humanely, tactically, and honorably. Wily Phenax's tricks, she tolerates; Mogis she despises most of all.