This is one of my many forgotten projects. When Theros came out and I went Devotion-crazy, I took a look at Shadowmoor/Eventide. But by the time I had played a lot of Theros block, I moved on to other projects, and here I am. The optimal cards for maximized devotion are those that are all-hydrid mana. I am not going to single them out, because it is obvious from looking at the mana symbol. Godhead of Awe, for example, is one of these.
Augury Adept: I need a way to make it unblockable. That's a lot of card draw on a 3-drop.
Barrenton Cragtreads: Limited.
Curse of Chains: Limited
Enchanted Evening: that is one awesome card. I must play it. In a battlefield where the total number of enchantments matter, this card would be really good. It reads casual as a 5-drop, though.
Glamer Spinners: its a weird late-game trick. Can't come up with a way to make it great.
Godhead of Awe: I would play it in an Exalted deck, except Exalted has gotten a lot of support in White/Black and White/Green. It would not be a devotion deck and I would have to run three colors adding black.
Mistmeadow Witch: the effect is a little heavy, but can be devastating. It would be really good against tokens, of course.
Plumeveil: Great stall card. Flash and Flying on any card get my attention.
Puresight Merrow: Misthollow Griffin?
Silkbind Faerie: Limited tapper.
Somnomancer: Limited tapper.
Steel of the Godhead: oh, there it is, that's my unblockable effect I was looking for. Nice!
Swans of Bryn Argoll: I don't know. Do I want my opponent to draw cards? I don't think so. In a lock-down deck, maybe.
Thistledown Duo: Limited.
Thistledown Liege: Must play, this is my devotion lord. Coming in as a 4-drop is not great for a lord. As a 3-drop, it would have been broken-good. Still a solid card.
Zealous Guardian: Limited.
Cemetery Puca: Very interesting. Not part of this devotion scan, though. Grixis with some Persist creatures, maybe?
Dire Undercurrents: definitely a 1-of or 2-of in a devotion experiment.
Ghatslord of Fugue: that's a really good pair of effects. Just the unblockable alone is pretty good. The exile clause is really good.
Glen Elendra Liege: devotion lord.
Gravelgill Axeshark: Limited.
Gravelill Duo: Limited.
Helm of the Ghastlord: a little too heavy, but great as a casual card.
Inkfathom Infiltrator: good for devotion.
Inkfathom Witch: Interesting effect. It can help your opponent's creatures... I am thinking about this one.
Merrow Grimeblotter: The untap effect is interesting. Reads restricted to specific situations.
Oona, Queen of the Fae: its a powerful effect with a ton of devotion mana. Its a six-drop, though.
Oona's Gatewarden: This card always reminds me of Michael Jackson. Limited.
Syge, River Cutthroat: that's a solid effect in a Grixis deck beating face. Not part of my devotion scan.
Torpor Dust: Limited.
Wanderdrine Rootcutters: Limited.
Wasp Lancer: nice devotion count.
Ashenmoor Gouger: great devotion count.
Ashenmoor Liege: devotion lord.
Demigod of Revenge: awesome card. I have played a lot. It has great devotion count, and if your opponent throws one in your graveyard, you get it back on the battlefield when you cast the next one. What is not to like!?
Emberstrike Duo: Limited.
Everlasting Torment: great card in any other deck than a devotion deck.
Fists of the Demigod: nice! This cycle is a must have.
Fulminator Mage: needs no introduction and too expensive for a casual devotion deck.