Lightning Bolt if you want quick, efficient damage (or even creature removal) for RDW.

Idea: Hordeling Outburst. 3 mana for 3 tokens? seems great for your deck.

Also, you probably don't need that many lands, as you have 4 (maybe 8) 3-costs.

This will be a staple (I thinK) for red-white aggro.

Consulate Ban {2}{r}

Instant

Counter target creature or artifact spell. Create a 1/1 white Soldier creature token.

Create the next card that will break Standard.

Important question: If this is the Cult of Emrakul, where's Emrakul?

Arabella, the Temptress {2}{r}{r/b}{b}

Legendary Creature - Demon Dryad

Flash

When Arabella enters the battlefield, any number of target creatures you don't control must attack you each turn if able. At least two creatures must be chosen

{1}{r}{b}: Target creature must block target creature this turn, or target creature must attack target player this turn.

5/3

I didn't really know how to do this.

Make a red/black angel, a green/white demon, or a green/red scientist. They must be on-color.

What power level simulator did you use? Also, neat deck! Never seen Azorius Mill before.

May your flight be swift

Sorry, need to change the wording a little bit:

Deck of Magic {3}

Artifact

{5}, {t}, exile a card from your hand: Pull a random card from your collection. If you cannot run it in your deck, reveal it and put it back and pull a new card. Repeat until you have a legal card. Then put it into your hand. You do not need to reveal it.

Silver-Bordered.

I added the 'if you're putting it back, reveal it first' thing.

Deck of Magic {3}

Artifact

{5}, {t}, exile a card from your hand: Pull a random card from your collection. If you cannot run it in your deck, put it back and pull a new card. Repeat until you have a legal card. Then put it into your hand. You do not need to reveal it.

Silver-Bordered.

I've liked this challenge. Create a card that feels like it should be in Beta.

Oh, sorry, forgot I needed to word Shadow Petal differently. Also, remember, the power nine are from Alpha.

Shadow Petal {1}

Mono Artifact

Adds 5 mana of any combination of colors of your choice to your mana pool, then is discarded. Tapping this artifact can be played as an interupt.

TypicalTimmy's challenge:

Aasimar Race

Enchantment - Aura Race

Enchanted Creature is a Bird in addition to their other types, has +0/-1, first strike, and flying.

Two challenges:

Make something that feels iconic to D&D

OR

Create a card that feels like it should be in alpha/beta.

Bookrook Oh okay. Here is your Alpha Artifact, that has the same power creep as Black Lotus (or maybe even worse power creep):

Shadow Petal {1}

Mono Artifact

{t}, Sacrifice Shadow Petal: Add 5 mana of any combination of colors.

Same as above challenge: Create a card that feels like it should be in alpha.

:3

Bookrook I'm confused on the last part "This card can’t untap until your next untap step." Doesn't it only untap at your next untap step?

Ashiok, Gilded Nightmare {2}{u}{b}{r}

+1: Exile the top card of target opponent's library. Create a Treasure token.

+1: You may cast target card from exile this turn.

-2: Sacrifice any amount of Treasure tokens. Exile the top two cards of each opponent's library for each sacrificed Treasure.

-10: Exile the top twenty cards of each player's library. Create five Treasure tokens.

5 Loyalty

Create a Mardu legendary. Goblins.

Bookrook Why has nobody done this yet? This is really interesting.

Rapid Debate {1}{U}

Instant

Counter target spell. Any player may pay {1} to copy this spell, targeting this spell.

Oh god, the confusion of the stack.

Do a black counterspell that's on-flavor. And it has to be mono-black or black-red. Good luck!

101 cards.

Yea, I understand that, that is a REALLY good combo, however. Especially if you put Worship in there, that is almost an insta-win. Just do a board wipe, swing, and win.

The only thing that gets past Avacyn, Angel of Hope + Dawnglade Regent is Exile All Creatures. Almost an insta-win, especially if you can get Worship.

seshiro_of_the_orochi just make it whenever a nontoken Soldier enters.

TypicalTimmy: In my set, the GW tribe is about Ally tokens and Horses (they have a cavalry army).

Undeniable Evidence {4}{g}{u}

Enchantment

When Undeniable Evidence enters the battlefield, create create Vixis, the Undeniable, a legendary 0/0 blue and green Fractal creature token with flying, trample, and 'When this creature dies, create a token that's a copy of it and put X +1/+1 counters on it, where X is this creature's power.'

When a Fractal you control enters, put two +1/+1 counters on it.

Create a legendary that you wish would've existed in Duskmourn, but didn't.

The tokens will be shuffled into your library, but it will cease to exist the next time state-based actions are checked.

May your flight be swift

Mana Resevoir {2}{u}{r}

Enchantment

If a player would lose unspent mana, instead deal 1 damage to them for each mana that player would lose.

Another spell that would pair ridiculously with this.

OR

A card that pairs with Horses and Allies in GW.