doctorhydrogen

manabasecrafter.com is a great place to see what lands are available in your colors

General bit of advice for a first deck:

1) Games (generally) are won by gaining incremental resource advantage turn by turn. That's not to say that people don't just blindly combo out for a turn six win from behind, but by and large the winner is the person who gets more done each turn. Getting more done may take the form of drawing more cards, making more dudes (tokens), ramping faster, stifling other people's resources, etc. Bake in resource advantage in a deck and you're already in good shape.

2) Have answers to everything. You're going to need targeted removal for artifacts, creatures, and enchantments, sweepers, graveyard hate, ways to hit indestructibles, etc. Obviously you're not going to always have an answer in your hand at all times, but you won't win without a chance to have one. Answers that can respond to multiple things are better yet, i.e. Maelstrom Pulse which can be targeted removal or hit a token swarm, Sever the Bloodline which can hit an indestructible or a token swarm, Deglamer which can get rid of an artifact or enchantment or indestructible Theros god, Golgari Charm which can save your entire board or wipe out a swarm of weenies, etc.

All that said, you're off to a good start. Mortify and Putrefy and Unmake are all great answers, land base looks decent, etc. Things I'd personally look at:

I hate to run without at least two board wipes. Damnation and Wrath of God are efficient (but expensive in the case of Damnation) but I'm a huge fan of Decree of Pain because drawing cards after wiping the board is a great knife in the back. Merciless Eviction and Austere Command are nice too because of the ways you can flex them to your needs, plus Eviction is a exile to it'll deal with Avacyn, Tajic, gods, etc.

Skullclamp is great in Ghave, so that's great for draw. I'd find a few more options. Deathreap Ritual is kind of a quiet all-star in any deck, but especially in one where you're going to be saccing tokens on the reg.

IMO Chromatic Lantern is an auto-include in any three color deck. It's just too useful. I'd probably run it over Darksteel Ingot if I had to choose.

Doubling Season is obviously a bomb in this deck, and I'm assuming you don't have on here because you don't have one. I'd pick one up someone; people absolutely PANIC when it hits the table in a deck with Ghave and that man planeswalkers.

If you want to be a dick you can run Dictate of Erebos, Grave Pact and Martyr's Bond and force everyone to sacrifice creatures every time you move a Ghave token around.

Braingeyser. Yeah, cool nostalgia points, but since you seem to be running a lot of counterspells you're probably not going to want to be tapping out on your turn to cast a sorc speed draw spell.

I'd find room for Render Silent, too. In a long game it can do the work of three counters. I'm not a huge fan of Remand in EDH (though it's a house in other formats) so that's probably what I'd replace, but clearly a lot of people don't agree with me about Remand so do what you will :) Maybe Mana Leak

I'd also run some artifact hate. You're not running any artifacts yourself, so Stony Silence or Energy Flux could be huge value in a format where 98% of people are running Sol Rings, Lightning Greaves, Signets, etc. I run Stony Silence in my no-artifact Sigarda deck and I've made people with artifact-heavy decks scoop just by putting it on the field. THAT is good value for two mana.

Sundial of the Infinite? As long as you don't mind missing your second main phase it lets you keep the angels you make.

I have a tough time believing anyone who is cool with having to sacrifice five creatures to a Grave Pact or Dictate on Prossh attack would get upset at a Druid's Repository, but to each his own.

IMO you probably need more answers. Unless you're running a deck where you're cheating creatures into play anything over 30 (or even 28) creatures feels like a lot of dead cards in hand when you with you had a way to deal with things. I very rarely look at my hand and think "I wish I had more creatures" but I do often think "I wish I had a way to deal with that thing".

Chaos Warp, Dreadbore, Hero's Downfall, Vandalblast, and maybe even Sever the Bloodline (for token swarms and indestructibles) would fit nicely, Chaos Warp especially. It's about your only way to hit enchantments, and in a multi-player game Vandalblast deals with a problem artifact and blows up all those annoying Sol Rings and Signets at the same time.

Bojuka Bog is a nice way to clean out someone's graveyard.

Cover of Darkness is great in vamp tribal. Giving all your dudes intimidate for two mana is fantastic.

Druid's Repository can make it almost impossible to keep Prossh off the field. Attack with Prossh and all kobolds, put a ton of counters on Druid's Repository, then sacc the kobolds, etc. Seriously, give it a look, it's AMAZING in Prossh, and it's become target number one for removal against my good friend's Prossh deck.

Fresh Meat is really stupid-good in this deck, too. Turning your half a dozen sacced kobolds into 2/2's is brutal.

Bear in mind it's an activated ability though, so you don't have to use it. It's not the kind of thing you'd be just turning on each turn. If you don't need it don't use it and let Derevi do her thing, but if someone tries to Doom Blade a creature, activate it and the Blade fizzles. Having the option to fizzle any targeted removal is super useful imo.

Alternatively you could just run something like Asceticism, which is not only useful in it's own right but it has the ability to regen stuff baked in. Plus it's hexproof and not shroud so it'll never affect Derevi.

Since you're running Sylvan Library you could also run Abundance. It's a useful card it it's own right, but if you get both down at the same time it lets you keep all three cards you draw with Sylvan Library at no life cost. I no longer run it in my Sigarda deck with Sylvan because I had to cut something, but there were times it was a really powerful combo.

IMO to run Dovescape you need to have a nuke on the field, and this isn't a deck with nukes. I run it in Bruna Light of Alabaster, but when I drop it I do so when Bruna is on the field with a handful of enchantments on her, hitting for 9 a swing with shroud, protection from creatures, lifelink and drawing me cards each turn. At that point I can afford to have the game turn into archenemy as everyone attacks me with the fistfull of doves they make. I most other situations it's going to result in you just get gang beaten out of the game.

Aerie Mystics is a nice bird to run in Bant to protect your dudes

I'm a huge fan of staying on theme, so if you don't want to run Storm Herd because they're not birds then I can't blame you a bit. Any jackass can cram 60 goodstuff cards into a deck and win a game; setting up rules for yourself and then winning while playing within that framework is 1000x cooler.

I like Grav Shift because it shuts down some decks totally. Edric decks filled with swarm critters, goblin and elf tribal, token decks, etc. all suddenly do zero damage without anthems in play, where as Serra Aviary helps all fliers so it's going to help some token decks, some Edric-type decks, etc. Plus it's like a fifty cent card or whatever, so it's easy to playtest and scrap if you think it doesn't work out. I'm a huge fan of it, though, at least against the decks I see a lot.

You could also try Crackdown. It's going to effect very few of your creatures, and it's going to wreck some other deck.

Render Silent is great in W/B as a counter.

With all those small reuseable artifacts Salvaging Station might be useful.

As useful a Sultai Charm is, I'd have a hard time running it over Beast Within.

You also look like you'll have trouble with indestructibles. I absolutely swear by Sever the Bloodline. It can hit an entire token line, then everyone forgets about it and three turns later you can flashback it to hit that Avacyn or Nylea that just got played.

Storm Herd would fit nicely.

I'd run Gravitational Shift over Serra Aviary.

Coastal Piracy and Bident of Thassa are going to draw you a ton of cards with this much evasion.

I'm working on a Bant flying matters deck with Jenara at the helm and I had missed Emeria Angel so I'll be taking that one :)

I should have tried to time it with Halloween

Wave of Vitriol and Primal Order would fit well in a deck with this many basics.

Grafted Wargear is really nice to put on stuff you're flinging.

Gift of Immortality lets you fling the same dude over and over

Well of Lost Dreams makes a great draw engine in a deck with a lifelink comander.

Preacher is great, here, too. Flinging someone else's stuff is doubly effective.

Kazul Tyrant of the Cliffs, Dragonmaster Outcast, and Rakka Mar make great fling generators, as does Mimic Vat and Seance.

Great call on Angelic Accord, I love that card and somehow it never occured to me to put it in my Brion deck. I'll be stealing that.

IMO you're running too many creatures and not enough answers. I'm only running 26 creatures in Edric and I sometimes drop three a turn. You can't drop that many and you're running 35. I'd slot in:

Chaos Warm- one of the few ways you can hit enchantments, but it'll deal with pretty much anything.

Terminate- Another creature removal

Sever the Bloodline- Exile effect to deal with indestructibles, doubles as removal for token swarms, can be used a second time from the graveyard due to flashback.

Black Sun's Zenith- Board wipe if things get out of control

Thirty lands seems a recipe for a lot of mulls, too, but maybe your group lets you mull without penalty so it's not an issue.

here's my variant: http://www.mtgvault.com/doctorhydrogen/decks/athreos-god-of-passage-edh/

It tends to play much more staxxy. The demons are useful, but by and large I win with a absurd army of tokens that are generated while everyone else's board state is locked down.

IMO the demons aren't what win the game. In reality how many are you going to possibly get out in a game, anyway?If your opponents are letting you summon up five demons and you haven't won then I don't see how another two or three is going to put you over the top.

Much more effective is what you chain off them, i.e. using Grave Pact and Dicate of Erebos to force your opponents to sacc six creatures when you summon one, using things like Ogre Slumlord or Xathrid Necro to poop out half a dozen tokens when you do it, etc.

In all honestly Shadowborn Apostles run much better in an Athreos deck than they do in Shirei, IMO, but it's much less budget friendly. It opens up ways to hit artifacts and enchantments, gives cool things like Edgewalker and Rememberence, etc.

There's a second component that makes it difficult to make work; simply by playing Zur everyone is going to assume you're running something degenerate (even if you're not) and just archenemy out out anyway.

I'd replace either Shattering Blow or Deicide with Return to Dust. It's also an exile effect, lets you hit both artifacts and enchantments, and if need be hit two targets.