Only a madman would submit a card after so many good submissions...
Engineered Blight BG
Enchantment - Aura
Enchant land in a graveyard
Lands that could produce mana of the type enchanted land could produce do not untap during their controller's untap step.
Thoughtweft Chatter Line 1W
Enchantment (U)
Kithkin you control lose vigilance.
Tapped an untapped Kithkin you control: another target creature gains first strike until end of turn. The Kithkin's ability to share thoughts was mostly a strategic boon, always updated on the enemy's fighting style, yet always distracted by the latest dank memes.
IIW: a card with Suspend that enters the battlefield tapped
Itchara, the Boundless GGG
Legendary Creature - Fungus God
Indestructible
Itchara enters the battlefield with a +1/+1 counter
Whenever a player casts a spell, you may put a +1/+1 counter on Itchara or move a +1/+1 counter on it to target creature.
You may cast spells with converted mana cost equal to Itchara's power without paying their mana cost.
0/1
Curse of Mourning UB
Enchantment - Aura Curse
Enchant player
Whenever a creature controlled by enchanted player dies, enchanted player skips his or her next untap step.
Grave Restock B
Sorcery
Return target creature card from your graveyard to your hand. If you do, and there are no other creature cards in your graveyard, reveal cards from the top of your library until you reveal a creature card, then put each revealed card into your graveyard. The Council of Responsible Sustainable Necromancy urges its followers to never take the last corpse without tossing in a fresh one.
Precession of the Zodiac 3BGU
Sorcery
Choose two creature types. Each player reveals his of her hand and exiles all cards of the first chosen type from hand, battlefield, and graveyard. Then each player puts all cards of the second chosen type from hand and graveyard onto the battlefield.
IIW: An Enchant Creature Aura that costs either WW, UU, BB, RR, or GG
Temporal Dominion - I really like the design neighborhood of this effect. However, I think, as shown by the very large mana cost, that the effect as it stands is too powerful to print and too powerful to be fun for all players. It's nice that the sweep mechanic means that this card can't be cheat-cast for less mana and give many many turns, but even a smaller number of turns, say 4 or 5, is too much for one card. This may been my favorite card if it were balanced in a different way: Sweep for islands, then take an extra turn for each 2 islands returned, and lower the mana cost to let it be cast outside of ramp/cheating.
Awakening of Jukai 3 - I can't judge this card without thinking of Endless Swarm, and the similarity ruins it for me. It would be a lot more interesting and unique if the card cost only 1 or 2 mana. If it did, that would allow the card to function as a kind of Exploration in a hypothetical lands deck that can manage to not cast any other spells. Bonus points must be acknowledged for creating a card both with Sweep and with Insects from the last challenge.
Oblong Surveyor - I like everything about the card except for the random 9 toughness. It does not need unfairly large toughness to be interesting. The second ability to lay down Wastes is very welcome because, as a Wastes matters card, players need a big incentive to restrict their mana to Wastes, since there are so many very good nonbasic colorless producing lands.
Urban Development - I got a chance to read this card before it was edited to Legendary lands coming into play tapped, and at that point it was my favorite card. This card is great because it synergizes with lands with multiple types, and nonbasic land tutoring is rare enough and powerful enough to get excited about. I don't think you needed to restrict to Legendary land - nonbasic already carried the flavor of "urban development". I also find the card less exciting when the lands enter tapped, though ultimately maybe that's more responsible.
Winner goes to Mergatroid_Jones' Oblong Surveyor, pretending it is a 3/3 or 3/4.
Honeybee 1G
Creature - Insect (C)
Flying
When Honeybee dies, destroy target creature if it has the least power or is tied for least power among creatures on the battlefield.
1/1
Master Telekine UU
Creature - Human Wizard (U) T: You may tap or untap another target nonland permanent. T: Attach target Aura with Enchant Creature or Equipment to target creature.
1/2
Rotmange Mongrel 1B
Creature - Zombie Hound (C)
Discard a card: Rotmange Mongrel gets -1/-1 and becomes the color of your choice until until of turn. Any player may activate this ability.
3/3
IIW: A card with a Phyrexian mana cost with CMC = 1
Blade of Rivalry 2
Artifact - Equipment (M)
Equip 4
Equipped creature has doublestrike, attacks each combat if able, and has "At end of turn, sacrifice this creature. If you do, attach Blade of Rivalry to target creature."
Rofellos' Summer Vacation G
Sorcery (M)
Create a green legendary enchantment token named "Rofellos' Retreat" that has "Return a permanent you control to its owner's hand: Add G to your mana pool."
Zaxium, Humble Researcher 0
(U) Legendary Creature - Human Wizard T: Draw a card. Activate this ability only if you control a permanent with a higher mana converted cost than every permanent controlled by an opponent.
"I'm nothing without my team and my lab."
0/1
Engineered Blight BG
Enchantment - Aura
Enchant land in a graveyard
Lands that could produce mana of the type enchanted land could produce do not untap during their controller's untap step.
IIW: Salt
Enchantment (U)
Kithkin you control lose vigilance.
Tapped an untapped Kithkin you control: another target creature gains first strike until end of turn.
The Kithkin's ability to share thoughts was mostly a strategic boon, always updated on the enemy's fighting style, yet always distracted by the latest dank memes.
IIW: a card with Suspend that enters the battlefield tapped
Legendary Creature - Fungus God
Indestructible
Itchara enters the battlefield with a +1/+1 counter
Whenever a player casts a spell, you may put a +1/+1 counter on Itchara or move a +1/+1 counter on it to target creature.
You may cast spells with converted mana cost equal to Itchara's power without paying their mana cost.
0/1
Next: Horse Assassin
Sorcery (C)
Detain all tapped creatures.
Draw a card.
IIW: something that changes colors
Enchantment - Aura Curse
Enchant player
Whenever a creature controlled by enchanted player dies, enchanted player skips his or her next untap step.
IIW: nontoken squirrels
Sorcery
Return target creature card from your graveyard to your hand. If you do, and there are no other creature cards in your graveyard, reveal cards from the top of your library until you reveal a creature card, then put each revealed card into your graveyard.
The Council of Responsible Sustainable Necromancy urges its followers to never take the last corpse without tossing in a fresh one.
IIW: a red Merfolk
Sorcery
Choose two creature types. Each player reveals his of her hand and exiles all cards of the first chosen type from hand, battlefield, and graveyard. Then each player puts all cards of the second chosen type from hand and graveyard onto the battlefield.
IIW: An Enchant Creature Aura that costs either WW, UU, BB, RR, or GG
Awakening of Jukai 3 - I can't judge this card without thinking of Endless Swarm, and the similarity ruins it for me. It would be a lot more interesting and unique if the card cost only 1 or 2 mana. If it did, that would allow the card to function as a kind of Exploration in a hypothetical lands deck that can manage to not cast any other spells. Bonus points must be acknowledged for creating a card both with Sweep and with Insects from the last challenge.
Oblong Surveyor - I like everything about the card except for the random 9 toughness. It does not need unfairly large toughness to be interesting. The second ability to lay down Wastes is very welcome because, as a Wastes matters card, players need a big incentive to restrict their mana to Wastes, since there are so many very good nonbasic colorless producing lands.
Urban Development - I got a chance to read this card before it was edited to Legendary lands coming into play tapped, and at that point it was my favorite card. This card is great because it synergizes with lands with multiple types, and nonbasic land tutoring is rare enough and powerful enough to get excited about. I don't think you needed to restrict to Legendary land - nonbasic already carried the flavor of "urban development". I also find the card less exciting when the lands enter tapped, though ultimately maybe that's more responsible.
Winner goes to Mergatroid_Jones' Oblong Surveyor, pretending it is a 3/3 or 3/4.
Next: 0 or 1 cost artifacts.
Creature - Insect (C)
Flying
When Honeybee dies, destroy target creature if it has the least power or is tied for least power among creatures on the battlefield.
1/1
IIW: a card with Kamigawa's Sweep mechanic
Creature - Human Wizard (U)
T: You may tap or untap another target nonland permanent.
T: Attach target Aura with Enchant Creature or Equipment to target creature.
1/2
IIW: A Crab Pirate
Creature - Zombie Hound (C)
Discard a card: Rotmange Mongrel gets -1/-1 and becomes the color of your choice until until of turn. Any player may activate this ability.
3/3
IIW: A card with a Phyrexian mana cost with CMC = 1
Artifact - Equipment (M)
Equip 4
Equipped creature has doublestrike, attacks each combat if able, and has "At end of turn, sacrifice this creature. If you do, attach Blade of Rivalry to target creature."
IIW: A flightless bird
Rofellos' Summer Vacation G
Sorcery (M)
Create a green legendary enchantment token named "Rofellos' Retreat" that has "Return a permanent you control to its owner's hand: Add G to your mana pool."
IIW: a narrow sweeper (examples: Whipflare, Hour of Reckoning)
(U) Legendary Creature - Human Wizard
T: Draw a card. Activate this ability only if you control a permanent with a higher mana converted cost than every permanent controlled by an opponent.
"I'm nothing without my team and my lab."
0/1
Aiming for a total opposite of Scornful Egotist
IIW: Ox, Oxen, or Ox-themed items/spells
Artifact Creature - Thopter (C)
Flying
Whenever an opponent attacks you, you may look at that player's hand.
0/2
IIW: A Morph card that costs something besides mana to unmorph. (Cost can still contain mana if you'd like, just require something else in addition)