Choose a creature type. Destroy all creatures that aren't of the chosen type.

[+2]: Discard a card, then draw a card. If a land card is discarded this way, draw an additional card.
[−3]: Return up to two target land cards from your graveyard to the battlefield.
[−11]: Destroy up to six target nonland permanents, then create six 2/2 green Cat Warrior creature tokens with forestwalk.
Lord Windgrace can be your commander.

As Mirrodin Besieged enters the battlefield, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with converted mana cost equal to 1 plus the sacrificed creature's converted mana cost, put that card onto the battlefield with an additional +1/+1 counter on it, then shuffle your library.

Menace
Whenever Overt Operative deals combat damage to a player, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

You may exert Rhonas's Stalwart as it attacks. When you do, it gets +1/+1 until end of turn and can't be blocked by creatures with power 2 or less this turn. (An exerted creature won't untap during your next untap step.)

Each other creature you control that's a Fungus or Saproling gets +1/+1.

When Squirrel Dealer enters the battlefield, ask a person outside the game "Do you like Squirrels?" If they do, create a 1/1 green Squirrel creature token.

Vigilance (Attacking doesn't cause this creature to tap.)
When Steadfast Sentry dies, put a +1/+1 counter on target creature you control.

, : Draw a card, then discard a card.

, : Roll a six-sided die. Create a number of 1/1 red Brainiac creature tokens equal to the result.
Tap three untapped Brainiacs you control: The next time you would roll a six-sided die, instead roll two six-sided dice and use the total of those results.

Protection from white (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything white.)
Unchained Berserker gets +2/+0 as long as it's attacking.

Draw three cards.
Adamant — If at least three blue mana was spent to cast this spell, scry 3.

Whenever you cycle another card for the first time each turn, create a 1/1 white Human Soldier creature token.
Cycling (, Discard this card: Draw a card.)

Whenever you cast a noncreature spell, draw a card.