Spells you control can't be countered. At the beginning of your end step, discover 5. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Indestructible Once each turn, you may pay {0} rather than pay the mana cost for a colorless spell that you cast from your hand.

Whenever another colorless creature enters the battlefield under your control, you may change Eldrazi Mimic's base power and toughness to that creature's power and toughness until end of turn.

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Vigilance {1}, {T}: Copy target activated or triggered ability you control from a colorless source. You may choose new targets for the copy. (Mana abilities can't be targeted.)

When you cast this spell, gain control of target creature until end of turn. Untap that creature. Until end of turn, it has base power and toughness 10/10, and gains trample, annihilator 2, and haste. Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.) Trample

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.

Untap Endbringer during each other player's untap step. {T}: Endbringer deals 1 damage to any target. {C}, {T}: Target creature can't attack or block this turn. {C}{C}, {T}: Draw a card.

When you cast this spell, draw four cards. Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents.) When Kozilek, Butcher of Truth is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

When you cast this spell, if you have fewer than seven cards in hand, draw cards equal to the difference. Menace Discard a card with mana value X: Counter target spell with mana value X.

({C} represents colorless mana.) When Matter Reshaper dies, reveal the top card of your library. You may put that card onto the battlefield if it's a permanent card with mana value 3 or less. Otherwise, put that card into your hand.

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

You may look at the top card of your library any time. You may cast artifact spells and colorless spells from the top of your library. {T}, Pay 1 life: Exile the top card of your library.

At the beginning of your upkeep, draw a card. {T}: Staff of Nin deals 1 damage to any target.

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

{T}: Add {C}. Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

{T}: Add {C}. {3}, {T}: Draw a card. Activate only if you control a creature with power 4 or greater.

{T}: Add {C}. {2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

{T}: Add {C}. {T}: Add {C}{C}. Spend this mana only to cast colorless Eldrazi spells or activate abilities of colorless Eldrazi.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Colorless Eldrazi spells you cast cost {2} less to cast. {7}, {T}: Search your library for a colorless creature card, reveal it, put it into your hand, then shuffle.

Guildless Commons enters the battlefield tapped. When Guildless Commons enters the battlefield, return a land you control to its owner's hand. {T}: Add {C}{C}.

{T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell. {2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life. {T}: Add {C}. {4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

If a spell or ability an opponent controls causes you to discard a card, you may reveal that card and put it on top of your library instead of putting it anywhere else. {T}: Add {C}.

When Radiant Fountain enters the battlefield, you gain 2 life. {T}: Add {C}.

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

{T}: Add {C}. {2}, {T}, Sacrifice Roadside Reliquary: Draw a card if you control an artifact. Draw a card if you control an enchantment.

{T}: Add {C}. {4}, {T}: Target creature can't be blocked this turn.

{T}: Add {C}. Whenever you cast a colorless spell with mana value 7 or greater, you may sacrifice Sanctum of Ugin. If you do, search your library for a colorless creature card, reveal it, put it into your hand, then shuffle.

{T}: Add {C}. {2}, {T}, Sacrifice a Desert: Exile all graveyards.

{T}: Add {C}. ({C} represents colorless mana.) {2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.

{T}: Add {C}. {T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

{T}: Add {C}. {6}, {T}, Sacrifice Spawning Bed: Create three 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this creature: Add {C}."

{T}: Add {C}. {2}, {T}: You gain 1 life for each colorless creature you control.

{T}: Add {C}. {X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

(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 {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

{T}: Add {C}. {3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

{T}: Add {C}.

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity. Equip commander {3} Equip {5}

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.) Equip {0}

Counter target spell or ability that targets a permanent you control. This spell costs {7} less to cast if it targets a spell or ability that targets a creature you control with power 7 or greater.

({C} represents colorless mana.) Trample, haste Whenever Reality Smasher becomes the target of a spell an opponent controls, counter that spell unless its controller discards a card.

Enchant creature Enchanted creature gets +10/+10 and has trample and annihilator 2. (Whenever it attacks, defending player sacrifices two permanents.)

Basalt Monolith doesn't untap during your untap step. {T}: Add {C}{C}{C}. {3}: Untap Basalt Monolith.

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

{T}: Add {C}{C}{C}. {3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.) Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked. {T}: Add {C} for each charge counter on Everflowing Chalice.

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Colorless creatures you control get +2/+2. Whenever you tap a permanent for {C}, add an additional {C}. Whenever you cast a colorless spell, you gain 2 life.

Trample Whenever Geode Golem deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

{T}: Add {C}{C}. {2}, {T}, Sacrifice Hedron Archive: Draw two cards.

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.

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you. {T}: Add {C}{C}.

Mana Vault doesn't untap during your untap step. At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault. At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you. {T}: Add {C}{C}{C}.

{T}: Add {C}. {1}, {T}, Sacrifice Mind Stone: Draw a card.

{1}, {T}, Sacrifice Moonsilver Key: Search your library for an artifact card with a mana ability or a basic land card, reveal it, put it into your hand, then shuffle.

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

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

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

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. When Solemn Simulacrum dies, you may draw a card.

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

Colorless spells you cast cost {2} less to cast. +1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand. −3: Destroy target permanent that's one or more colors.

Each player sacrifices all permanents they control that are one or more colors.

Whenever Bane of Bala Ged attacks, defending player exiles two permanents they control.

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.) Whenever an opponent sacrifices a nontoken permanent, put that card onto the battlefield under your control.

Annihilator 3 (Whenever this creature attacks, defending player sacrifices three permanents.) Pathrazer of Ulamog can't be blocked except by three or more creatures.

Exile target permanent.

({C} represents colorless mana.) When Thought-Knot Seer enters the battlefield, target opponent reveals their hand. You choose a nonland card from it and exile that card. When Thought-Knot Seer leaves the battlefield, target opponent draws a card.

As an additional cost to cast this spell, reveal a colorless creature card from your hand. Exile target creature if its power is less than or equal to the revealed card's power.

+2: Ugin, the Spirit Dragon deals 3 damage to any target. −X: Exile each permanent with mana value X or less that's one or more colors. −10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.

When you cast this spell, exile two target permanents. Indestructible Whenever Ulamog, the Ceaseless Hunger attacks, defending player exiles the top twenty cards of their library.

When you cast this spell, destroy target permanent. Indestructible Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents.) When Ulamog, the Infinite Gyre is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

As an additional cost to cast this spell, reveal a colorless creature card from your hand. Exile each creature and planeswalker with mana value less than the revealed card's mana value.

If you would lose unspent mana, that mana becomes colorless instead.

If a player would begin an extra turn, that player skips that turn instead. If Ugin's Nexus would be put into a graveyard from the battlefield, instead exile it and take an extra turn after this one.