As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

{T}: Add {C}{C}. Spend this mana only to cast Myr spells or activate abilities of Myr. {3}, {T}: Return target Myr card from your graveyard to your hand.

{T}: Create a 1/1 colorless Myr artifact creature token. {T}, Tap five untapped Myr you control: Search your library for a Myr creature card, put it onto the battlefield, then shuffle.

{T}: Add {C}{C}.

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.) Equip {1}

{2}{W}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.) Whenever one or more +1/+1 counters are put on Knighted Myr, it gains double strike until end of turn.

Whenever you cast an artifact creature spell, it gains sunburst. (It enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.) At the beginning of your end step, if there are thirty or more counters among artifacts and creatures you control, Lux Artillery deals 10 damage to each opponent.

{T}: Add one mana of any color.

Creature tokens you control have haste. At the beginning of combat on your turn, create a 2/1 blue Phyrexian Myr artifact creature token. Then you may choose a token you control. If you do, each other token you control becomes a copy of that token.

{T}: Add {G}.

{T}: Add {W}.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.) Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

{T}: Add {R}.

{T}: Add {B}.

Prevent all combat damage that would be dealt to attacking artifact creatures you control. Whenever one or more artifact creatures enter the battlefield under your control, draw a card. This ability triggers only once each turn.

Changeling (This card is every creature type.) {X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

When Myr Battlesphere enters the battlefield, create four 1/1 colorless Myr artifact creature tokens. Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) {T}, Pay 2 life: Add one mana of any color.

Other Myr creatures you control get +1/+1. {1}, {T}: Untap each other Myr you control.

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

{T}: Add {C}{C}.

Ward {2} As Roaming Throne enters the battlefield, choose a creature type. Roaming Throne is the chosen type in addition to its other types. If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Flash You may cast artifact spells as though they had flash.

{T}: Add {U}.

At the beginning of your precombat main phase, choose one or more — • Sell Contraband — Create a Treasure token. You lose 1 life. • Buy Information — Draw a card. You lose 2 life. • Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

At the beginning of your upkeep, you draw a card and you lose 1 life.

Draw a card for each creature you control. Ferocious — You gain 4 life for each creature you control with power 4 or greater.

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead. If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

As Kindred Discovery enters the battlefield, choose a creature type. Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

If Leyline of the Guildpact is in your opening hand, you may begin the game with it on the battlefield. Each nonland permanent you control is all colors. Lands you control are every basic land type in addition to their other types.

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.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Choose one. If you control a commander as you cast this spell, you may choose both instead. • Creatures you control gain flying, vigilance, and double strike until end of turn. • Creatures you control gain lifelink, indestructible, and protection from all colors until end of turn.

Tap target creature. Metalcraft — If you control three or more artifacts, exile that creature.

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

If you control a commander, you may cast this spell without paying its mana cost. Creatures you control gain indestructible until end of turn.

Kicker {2}{W} (You may pay an additional {2}{W} as you cast this spell.) Target creature phases out. If this spell was kicked, each creature target player controls phases out instead. (Treat phased-out creatures and anything attached to them as though they don't exist until their controller's next turn.)

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

{T}: Add {C}. {T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

{T}: Add {C}. {T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

{T}: Add {G}. Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{T}: Add {C}. {T}: Add {G} or {W}. Brushland deals 1 damage to you.

{T}: Add {C}. {T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

{T}: Add one mana of any color in your commander's color identity.

{T}: Add one mana of any color that a land an opponent controls could produce.

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

({T}: Add {G}.)

({T}: Add {W} or {B}.) As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {W} or {U}.) As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {U}.)

{T}: Add {C}. {T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

{T}: Add {C}. {T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

({T}: Add {R}.)

{T}: Add {U}. Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

({T}: Add {B} or {G}.) As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Path of Ancestry enters the battlefield tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

({T}: Add {W}.)

You have no maximum hand size. {T}: Add {C}.

({T}: Add {R} or {W}.) As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{T}: Add {C}. {T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

({T}: Add {G}, {W}, or {U}.) Spara's Headquarters enters the battlefield tapped. Cycling {3} ({3}, Discard this card: Draw a card.)

({T}: Add {U} or {R}.) As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {R} or {G}.) As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {G} or {W}.) As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{T}: Add {C}. {T}: Add {U} or {B}. Underground River deals 1 damage to you.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Urza's Saga gains "{T}: Add {C}." II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'" III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

({T}: Add {U} or {B}.) As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

If you control a commander, you may cast this spell without paying its mana cost. You may choose new targets for target spell or ability.

Permanents you control gain hexproof and indestructible until end of turn.

Return target nonland permanent you don't control to its owner's hand. Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.