Illulia's Watcher1B
Creature - Eye
Flying
When ~ dies, put a -1/-1 counter on target creature. "Don't hide. You can't escape my gaze of hate." - Illulia of Nighthearth
1/1
(strange that a card as simple as that doesn't exist yet o_O)
Revenge of the Damned2WBR
Sorcery
Return each creature with converted mana cost 2 or less from your graveyard to the battlefield. Those creatures get +3/+0 and gain haste and double strike until end of turn.
Boros Bazaar Guard4W
Creature - Human Soldier
First Strike
Sacrifice ~: Exile target nonland permanent that entered the battlefield this turn if it's mana cost hasn't been paid to cast it.
2/2
Sheltering Arms1W
Instant
Convoke
Prevent all damage that would be dealt to target creature or player this turn. If a creature was tapped to cast ~, draw a card.
Next: Volcanic Spawn
Neverending Dreams
Realm of Irreality
Riptide Growth Chamber
Land
You may choose not to untap ~ during your untap step. T: Add 1 to your mana pool. UG, T: Tap target creature you control. As long as ~ remains tapped, that creature doesn't untap during its controller's untap step and has "At the beginning of your upkeep, put a +1/+1 counter on this creature".
However, it may be possible to style them into grizzled nomadic survivors who wander the desert, perhaps in search of something lost - such as the ruins of their old civilization, or relics.
Maybe they have a religious motivation. They could haven been told by one of their gods to fulfill some kind of duty, which they seek to fulfill. In order to do that, they mainly roam the desert as nomads, but also attack and other people who violate their codex, ethic or something like that. Religious zealotry is a good theme for RW I think.
I'm liking land theme a bit more. But, then, how do you differentiate that from ZEN? Is there enough design space?
Well, ZEN was all about getting more land onto the table. There was lot of ramp, effects triggering off lands entering the battlefield etc. But in the 'fertile crescent' set, the focus would be less on getting more and more lands (since all you could get would be 'desert' anyway) but concentrating on the ones you have, optimizing them and making them more effective (fortifications?). Since it's only a subtheme, it doesn't need much design space, but fits quite nicely with the flavor.
Your flavor suggestions sound great to me. As I said before, I think mechanics communicating the bleakness and scarceness of resources would be very fitting as a 'core' (maybe the necropolis kingdoms were formed in the first place because there were not enough 'human resources' left?).
The crocodile tribe sounds great. An 'egyptian' setting would be very interesting - even if it just showed that MTG doesn't turn into Yu-Gi-Oh because of a similar flavor focus
For the 'core': I find it really hard coming up with something from the mechanical angle, especially because you can't just slam '[insert card type here] block' on the whole thing. Except from graveyard, artifact and land; an enchantment, instant/sorcery or library block would still be possible, but as movexig already pointed out, those things don't quite fit the flavor of an 'egyptian' set. But as we've seen in time spiral, blocks can also have pretty abstract themes ('time' etc).
Maybe it is easier from a top-down perspective. Innistrad was a 'graveyard block' because the world had a horror-like setting with loads of zombies, spritis and other monsters. Mirrodin was an artifact block because the world was made of metal. Ravnica was a multicolor block because of the guilds.
What influences the inhabitants of a plane mostly covered by uninhabitable desert most? I think if you have this down, coming up with a fitting 'core' mechanic isn't so difficult. Since resources are scarce and you have to manage them well in such a harsh environment, lands could in fact be a fitting subtheme.
I like "enchantment matters" as a subtheme, but I'm not really sure that it's big enough to carry a block. Let's brainstorm it anyway, though. What kinds of mechanics can we make with "enchantments matter"?
Yvvar, the Obscuring Veil2UU
Legendary Creature - Illusion
Hexproof, Flying U, T: Creatures are unblockable until end of turn. Put ~ on top of your library. Slowly, it creeps. Slowly, it covers. Slowly, it fades.
2/3
Uulac, the Ever-Growing4GG
Legendary Creature - Ooze
Trample
Whenever you cast a spell, you may put X +1/+1 counters on ~, where X is that spell's converted mana cost. Since generations of godtrackers disappeared while worshipping it, Uulac has become the only nayan god left alone and untouched by rituals. 1/1
Mwonvuli Elder3GG
Creature - Ape Shaman
Intimidate
~ gets +1/+1 for each other creature with a static ability on the battlefield. He is merely an impersonation of the jungle's diversity.
3/3
Oni's SutraBR
Enchantment
At the beginning of your upkeep, put a verse counter on ~.
Creatures you control can't block and get +X/+0, where X is the number of verse counters on ~.
Next: Kagemaro's Grudge
Ral's Cunning
Kemba's Will
Hardshell Bodyguards1UB
Creature - Oyster Mercenary
Defender
Whenever ~ blocks a creature, put a -1/-1 counter on that creature and tap it. It doesn't untap during its controller's next untap step.
0/4
Tower of the Speakers
Legendary Land T: Add W to your mana pool. W, T, tap three untapped creatures you control: Choose a card type. Until the beginning of target opponent's next end step, he or she can't cast cards of the chosen type. The voice of many silences the individual.
Artifact Creature - Elf Dreadnought
Infect
~ attacks each turn if able.
All creatures able to block ~ do so.
5/2
Next: Beast Citizen
(they are tokens with the creature type Citizen.)
Creature - Eye
Flying
When ~ dies, put a -1/-1 counter on target creature.
"Don't hide. You can't escape my gaze of hate." - Illulia of Nighthearth
1/1
(strange that a card as simple as that doesn't exist yet o_O)
Sorcery
Return each creature with converted mana cost 2 or less from your graveyard to the battlefield. Those creatures get +3/+0 and gain haste and double strike until end of turn.
Next: 1URG
Creature - Human Soldier
First Strike
Sacrifice ~: Exile target nonland permanent that entered the battlefield this turn if it's mana cost hasn't been paid to cast it.
2/2
Next:
Sacromite Golem
Blazing Blade
Orzhova Taxes
Instant
Convoke
Prevent all damage that would be dealt to target creature or player this turn. If a creature was tapped to cast ~, draw a card.
Next:
Volcanic Spawn
Neverending Dreams
Realm of Irreality
Land
You may choose not to untap ~ during your untap step.
T: Add 1 to your mana pool.
UG, T: Tap target creature you control. As long as ~ remains tapped, that creature doesn't untap during its controller's untap step and has "At the beginning of your upkeep, put a +1/+1 counter on this creature".
Next:
Tarmogoyf's Roar
Aven Cloudweaver
Wilting Dryad
Maybe they have a religious motivation. They could haven been told by one of their gods to fulfill some kind of duty, which they seek to fulfill. In order to do that, they mainly roam the desert as nomads, but also attack and other people who violate their codex, ethic or something like that. Religious zealotry is a good theme for RW I think.
Well, ZEN was all about getting more land onto the table. There was lot of ramp, effects triggering off lands entering the battlefield etc. But in the 'fertile crescent' set, the focus would be less on getting more and more lands (since all you could get would be 'desert' anyway) but concentrating on the ones you have, optimizing them and making them more effective (fortifications?). Since it's only a subtheme, it doesn't need much design space, but fits quite nicely with the flavor.
Your flavor suggestions sound great to me. As I said before, I think mechanics communicating the bleakness and scarceness of resources would be very fitting as a 'core' (maybe the necropolis kingdoms were formed in the first place because there were not enough 'human resources' left?).
For the 'core': I find it really hard coming up with something from the mechanical angle, especially because you can't just slam '[insert card type here] block' on the whole thing. Except from graveyard, artifact and land; an enchantment, instant/sorcery or library block would still be possible, but as movexig already pointed out, those things don't quite fit the flavor of an 'egyptian' set. But as we've seen in time spiral, blocks can also have pretty abstract themes ('time' etc).
Maybe it is easier from a top-down perspective. Innistrad was a 'graveyard block' because the world had a horror-like setting with loads of zombies, spritis and other monsters. Mirrodin was an artifact block because the world was made of metal. Ravnica was a multicolor block because of the guilds.
What influences the inhabitants of a plane mostly covered by uninhabitable desert most? I think if you have this down, coming up with a fitting 'core' mechanic isn't so difficult. Since resources are scarce and you have to manage them well in such a harsh environment, lands could in fact be a fitting subtheme.
Curses, enchantment creatures and aura mechanics come to mind first...
Legendary Creature - Illusion
Hexproof, Flying
U, T: Creatures are unblockable until end of turn. Put ~ on top of your library.
Slowly, it creeps. Slowly, it covers. Slowly, it fades.
2/3
Next: Cryptic Annelid, Char-Rumbler or Heartwood Storyteller
Legendary Creature - Ooze
Trample
Whenever you cast a spell, you may put X +1/+1 counters on ~, where X is that spell's converted mana cost.
Since generations of godtrackers disappeared while worshipping it, Uulac has become the only nayan god left alone and untouched by rituals.
1/1
Next: Ophidian or Transluminant
Creature - Ape Shaman
Intimidate
~ gets +1/+1 for each other creature with a static ability on the battlefield.
He is merely an impersonation of the jungle's diversity.
3/3
Enchantment
At the beginning of your upkeep, put a verse counter on ~.
Creatures you control can't block and get +X/+0, where X is the number of verse counters on ~.
Next:
Kagemaro's Grudge
Ral's Cunning
Kemba's Will
Creature - Oyster Mercenary
Defender
Whenever ~ blocks a creature, put a -1/-1 counter on that creature and tap it. It doesn't untap during its controller's next untap step.
0/4
Next: Drake Fungus
Legendary Land
T: Add W to your mana pool.
W, T, tap three untapped creatures you control: Choose a card type. Until the beginning of target opponent's next end step, he or she can't cast cards of the chosen type.
The voice of many silences the individual.
Next:
Rhystic Progress
Neverending Dreams
Choking Overgrowth