Minor God Analysis!
Totally Playable
Athreos: See above
Mostly Playable
Ephara: Does well in a subset of decks, gives low curve decks long-term gas, benefits from flash creatures and
moorland haunt in the ULD.
Keranos: I think he's a little slow, but if you have a deck that can stall he probably wins you the game.
Pharika: She's pretty good. Repeated deathtouch is really annoying and there are so many other cards in that niche you can pass on her even if she's on target for your themes.
Barely Playable
Xenagos: Once in a blue moon you'll get him with something that is amazing, but usually you'll wish he was another dude. He's still in my list, for what that's worth, but I doubt he will make the current cut when all is said and done.
Iroas: The opponent basically can never block you profitably, if at all. Completely useless if you are on the defensive and does nothing to help the problem getting your creatures getting removed. If your opponent is trying to stabilize with blockers, he wins the game. If they stabilize with a wrath, you will wish you had another creature to threaten with instead. Too narrow for most lists.
Mogis: 2 damage a turn for a 4 drop is below the going rate, particularly with the option to mitigate present. Not very interesting to deal with: you either can generate bodies and he does nothing, or you can't and take some damage.
Basically Unplayable
Phenax: So, so narrow. I tried him out thinking he cost four. He wasn't good.
Karametra: Spending 5 mana to get more land isn't very interesting.
Kruphix: Basically does nothing for 5 mana.