Flyers !!
1 x Ravos, Soultender
1 x Ishai, Ojutai Dragonspeaker


1 x Angelic Field Marshal
1 x Arcane Sanctum
1 x Azorius Chancery
1 x Azorius Keyrune
1 x Azorius Signet
1 x Baleful Strix
1 x Banishing Light
1 x Bident of Thassa
1 x Bloodgift Demon
1 x Bone Shredder
1 x Caves of Koilos
1 x Command Tower
1 x Curator of Mysteries
1 x Demon of Wailing Agonies
1 x Dimir Aqueduct
1 x Drana, Liberator of Malakir
1 x Emeria Angel
1 x Esper Stormblade
1 x Ethersworn Adjudicator
1 x Evolving Wilds
1 x Favorable Winds
1 x Fellwar Stone
1 x Gravitational Shift
1 x Guardian Seraph
1 x Herald of the Host
1 x Hypnotic Siren
11 x Island
1 x Isperia the Inscrutable
1 x Isperia, Supreme Judge
1 x Kitesail Freebooter
1 x Lieutenant Kirtar
1 x Lingering Souls
1 x Magister Sphinx
1 x Medomai the Ageless
1 x Migratory Route
1 x Military Intelligence
1 x Mirrodin's Core
1 x Mulldrifter
1 x Necropolis Regent
1 x Needle Specter
1 x Nimble Obstructionist
1 x Oblivion Ring
1 x Orzhov Basilica
1 x Orzhov Signet
1 x Pilgrim's Eye
8 x Plains
1 x Prismatic Lens
1 x Quickling
1 x Radiant, Archangel
1 x Selfless Spirit
1 x Sharding Sphinx
1 x Shimian Specter
1 x Silumgar Sorcerer
1 x Siren of the Silent Song
1 x Siren Stormtamer
1 x Sol Ring
1 x Spear of Heliod
1 x Spiketail Drakeling
1 x Spiketail Hatchling
1 x Spirit Bonds
1 x Sprite Noble
1 x Stormscape Familiar
1 x Sunblast Angel
6 x Swamp
1 x Swiftfoot Boots
1 x Terramorphic Expanse
1 x Thopter Spy Network
1 x Thunderclap Wyvern
1 x True Conviction
1 x Vampire Nighthawk
1 x Vault of Whispers
1 x Visara the Dreadful
1 x Warden of Evos Isle
1 x Windborn Muse
1 x Windreader Sphinx
1 x Wispmare
1 x Zur the Enchanter


Deck built mostly around Flying and the abilities of Ravos. Ishai in this deck is just a tactical battering ram. Which is good by itself, of course, but not something to build around.

For easy bookkeeping, all creatures have Flying.

Ravos graveyard package: cards you can easily get into graveyard for value, then get back with Ravos, then repeat the process. When you stop the loop, they become synergistic beaters.
Bone Shredder
Curator of Mysteries
Lieutenant Kirtar
Mulldrifter
Nimble Obstructionist
Selfless Spirit
Silumgar Sorcerer
Siren Stormtamer
Spiketail Drakeling
Spiketail Hatchling
Wispmare

Ravos "go wide" package
Emeria Angel
Herald of the Host
Lingering Souls
Migratory Route
Needle Specter (Nothing really "go wide", but gets super good when buffed with anthems)
Sharding Sphinx (5 other artifact creatures plus Azorius Keyrune plus Thopter Spy Network (what a combo))
Spirit Bonds
Thopter Spy Network (More than 15 artifacts in the deck)
PLUS
Bident of Thassa
Drana, Liberator of Malakir
Favorable Winds
Gravitational Shift
Necropolis Regent (Damn, what a stupid card)
Radiant, Archangel
Spear of Heliod
Sprite Noble
Thunderclap Wyvern
True Conviction (SO GOOD WHEN YOU HAVE AN ANTHEM COMMANDER)
Windreader Sphinx

Flyer synergy:
Isperia the Inscrutable
Military Intelligence
Warden of Evos Isle
Bident of Thassa
Drana, Liberator of Malakir
Favorable Winds
Gravitational Shift
Necropolis Regent (Damn, what a stupid card)
Radiant, Archangel
Sprite Noble
Thunderclap Wyvern
Windreader Sphinx

Not included:
Pride of the Clouds (price)
Archon of Redemption (low impact for high mana cost (?))

Zur package:
Spear of Heliod
Banishing Light
Oblivion Ring
Favorable Winds
Spirit Bonds
Military Intelligence

I'm ringing up Pride of the Clouds at ~$6. Just confirming if you meant price was too expensive for this deck's budget.

Depending on how hard you are on the "everything must fly" rule, you may not care for these suggestions, but I'll throw them out there anyway:
Aboshan, Cephalid Emperor
Deluge
Magus of the Moat <- If your budget is what Pride of the coulds is referring to, then this is also out of range at ~$8
Moat Just kidding! =p
Stormtide Leviathan
Blinding Angel <-Not sure what your budget is, but she's ~$2.50-$3
Serra Aviary <-note that this also buffs your opponents' fliers so maybe not worth it.
Dictate of Heliod
Glorious Anthem <-fetchable by Zur, $1.50-$2
Signal Pest
Skyblinder Staff
Smog Elemental
Soulcatcher
Sunscorch Regent <-backup Ishai

More artifacts for your Thopter Spy Network:
Dimir Signet
Ancient Den <-$3.50
Seat of the Synod <-$2 (amusingly enough the more played one has been reprinted enough times that it's actually cheaper)

This next one would be a huge change, but if Ishai is only in there as a battering ram, possibly consider Kraum because he gives you access to a fourth color? Ishai could still be in the 99 if you still want him.
Red also gives you access to all those delicious Earthquake effects that don't hit fliers.
Speaking of red, I found a card I'm seriously considering putting in my dragons deck, now that I know it exists, that yours may also like: Mudslide. <- Note that it is fetchable by Zur.

Of course the downside of going up to 4 colors is that your mana base either gets worse or more expensive($$).

Edit: You have 35 lands. If you can bring yourself to do it, I suggest 38.
Also, your deck only has 1 board wipe that I see (sunblast Angel), consider bringing that number closer to 5.
You have 8 ramp, that's probably fine. I like 10, but it's not a hard number.
Spot removal (at least 5) and cardflow (at least 10) are plenty well represented in numbers, but I might make one of your creature spot removals into one more thing that could hit an artifact (Cast out?). Relying solely on Oblivion Ring makes me a little wary.
You also might want to make Encroaching Wastes ($0.25), Tectonic Edge ($1.50), and/or Ghost Quarter ($2) one or two of the lands you add to the deck so you have effects that can hit problematic lands such as Itlimoc, Cradle of the Sun.