Well, here are some of the card ideas I that were posted on the Dojo. Half were mine, the others were from various people at the Dojo.
White
???, WWW
Enchantment, Rare
During your upkeep, sacrifice 2 lands, or bury ???
Reduce all damage dealt to you to 0.
???, WW
Sorcery, Rare
Remove target artifact from the game. It's controller gains life equal to it's converted mana cost.
Blue
???, 1U
1/1, Sorcerer, Common
U, tap: Tap target creature
???, 1U
1/1, Sorcerer, Common
U, tap: Tap target Artifact.
???, 1U
1/1, Sorcerer, Common
U, tap: Tap target Land
???, UU
1/1, Merfolk, Uncommon
tap, target creature cannot be the target of spells or abilities until end of turn.
Krakken, 4UUU
9/9, Legendary Monster, Rare
Krakken doesn't untap during your untap phase.
To untap Krakken, sacrifice a land.
Play this ability only during you upkeep.
Triton, 3UU
3/3, Legendary Merfolk, Rare
tap: Triton deals 2 damage to target creature or player.
All Merfolk gain +1/+1
Black
???, B
2/2, Imp, Uncommon
Flying
When ??? comes into play, discard a card at random.
Cerebus, 3BB
5/3, Legendary Beast, Rare
Cerebus may only be blocked by three or more creatures
Cerebus may block up to three creatures.
Medusa, 3BB
3/3, Legend, Rare
2B, tap: Destroy target attacking or blocking creature.
Traitorous Priest, 1B
2/2, Cleric, Uncommon
When Traitorous Priest comes into play, choose a player. That player gains control of Traitorous Priest.
Whenever Traitorous Priest becomes tapped, target opponent gains 2 life.
Red
Terk, Mogg Chieftan, 3RR
3/3, Goblin Legend, rare
When Terk, Mogg Chieftan comes into play, you may search your library for up to two goblins and put them into play. If either of the goblins put into play this way has a converted mana cost above 3, sacrifice them at the end of your turn.
Ancient Wyrm, 4RRR
5/5, Dragon, Rare
Flying
1RR, Ancient Wyrm deals 2 damage to target creature or player.
???, 2RR
Sorcerery, Uncommon
Until the end of turn, any player may sacrifice a land to bury target land.
Initiate of the Flames, 1R
1/1 Sorcerer, common
tap, Initiate of the flames deals 1 damage to target creature and 1 damage to itself.
RR: Initiate of the Flames gains Protection from Red until the end of turn.
Priest of the Flames, 2R
1/2, Sorcerer, uncommon
R, tap: Priest of the Flames deals 2 damage to target creature or player, and 2 damage to itself.
RR: Priest of the Flames gains Portection from Red until the end of turn.
Green
Llanowar Captian, GG
1/1, Elf, Uncommon
Whenever a green creature comes into play, you may pay G to draw a card.
I have more that I will post later if anyone wants them.
