For each attacking creature, its owner puts it on the top or bottom of their library.

Changeling (This card is every creature type.)

{T}: Target creature gains all creature types until end of turn.

{T}: Target creature loses all creature types until end of turn.

When Amphin Mutineer enters the battlefield, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.

Encore {4}{U}{U} ({4}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

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

Return target card from your graveyard to your hand.

Bala Ged Sanctuary enters the battlefield tapped.

{T}: Add {G}.

{T}: Add {G}.

{T}: Add {U}.

Equipped creature has deathtouch and lifelink.

Equip {2}

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Untap all creatures. Until end of turn, whenever a creature an opponent controls blocks, draw a card.

Draw a card.

Prevent all damage that would be dealt to creatures this turn. Creatures you control gain hexproof until end of turn. (They can't be the targets of spells or abilities your opponents control.)

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {G} or {U}.

({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.

Whenever Chambered Nautilus becomes blocked, you may draw a card.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

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

At the beginning of your upkeep, you may exile Cosima. If you do, it gains "Whenever a land enters the battlefield under your control, if Cosima is exiled, you may put a voyage counter on it. If you don't, return Cosima to the battlefield with X +1/+1 counters on it and draw X cards, where X is the number of voyage counters on it."

Whenever a Vehicle you control deals combat damage to a player, that player exiles that many cards from the top of their library. You may play lands from among those cards for as long as they remain exiled.

Crew 1

As an additional cost to cast this spell, sacrifice a land.

Search your library for a land card, put that card onto the battlefield, then shuffle.

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Target creature gets +3/+3 until end of turn. All creatures able to block it this turn do so.

Prevent all combat damage that would be dealt to attacking creatures you control.

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands.

{T}: Add {G} or {U}.

Whenever Drelnoch becomes blocked, you may draw two cards.

Whenever a creature deals combat damage to one of your opponents, its controller may draw a card.

Whenever Elven Warhounds becomes blocked by a creature, put that creature on top of its owner's library.

Whenever Engulfing Slagwurm blocks or becomes blocked by a creature, destroy that creature. You gain life equal to that creature's toughness.

{G}, Sacrifice a creature: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

{T}: Add {C}.

{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

You may have Glasspool Mimic enter the battlefield as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Shore enters the battlefield tapped.

{T}: Add {U}.

You and permanents you control have protection from Salamanders.

At the beginning of your end step, each player who controls the fewest creatures creates a 4/3 blue Salamander Warrior creature token.

Whenever a creature you control becomes blocked, you may return it to its owner's hand.

Whenever one or more creatures you control deal combat damage to a player, draw a card.

Flash

Commander creatures you control get +2/+2.

Commanders you control have hexproof.

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

{T}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

Enchant creature, land, or planeswalker

Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Whenever equipped creature becomes blocked by a creature, you may draw two cards.

Equip {1}

Creatures don't untap during their controllers' untap steps.

Whenever a creature enters the battlefield, untap all creatures.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

-1: Untap target permanent.

Enchant creature

All creatures able to block enchanted creature do so.

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Imprint -- Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.

{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

{1}{U}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

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

Choose target nonlegendary creature. The next time one or more creatures or planeswalkers enter the battlefield this turn, they enter as copies of the chosen creature.

Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

All creatures able to block equipped creature do so.

Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

If you control a commander, you may cast this spell without paying its mana cost.

Prevent all damage that would be dealt this turn by creatures your opponents control.

Counter target spell.

At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

({U/P} can be paid with either {U} or 2 life.)

You may have Phyrexian Metamorph enter the battlefield as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Enchant creature

Enchanted creature gets +3/+3, must be blocked if able, and is goaded. (It attacks each combat if able and attacks a player other than you if able.)

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.

Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.

{T}: Add {G} or {U}.

You have no maximum hand size.

{T}: Add {C}.

All creatures able to block target creature this turn do so.

Ferocious -- That creature gains indestructible until end of turn if you control a creature with power 4 or greater.

Whenever Saprazzan Heir becomes blocked, you may draw three cards.

{3}{G}: Target creature must be blocked this turn if able.

{T}: Add {C}.

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

Draw cards equal to the number of cards in your hand plus one. You have no maximum hand size for the rest of the game.

As Sea Gate, Reborn enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {U}.

All creatures able to block Shinen of Life's Roar do so.

Channel -- {2}{G}{G}, Discard Shinen of Life's Roar: All creatures able to block target creature this turn do so.

{1}, {T}: Add {G}{U}.

Whenever Slith Strider becomes blocked, draw a card.

Whenever Slith Strider deals combat damage to a player, put a +1/+1 counter on it.

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

Choose a creature type other than Wall. Each creature becomes that type until end of turn.

Hexproof

Lieutenant -- As long as you control your commander, Stormsurge Kraken gets +2/+2 and has "Whenever Stormsurge Kraken becomes blocked, you may draw two cards."

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Whenever Sylvan Basilisk becomes blocked by a creature, destroy that creature.

{T}: Add {C}.

{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Whenever Tangle Asp blocks or becomes blocked by a creature, destroy that creature at end of combat.

Tanglepool Bridge enters the battlefield tapped.

Indestructible

{T}: Add {G} or {U}.

{G}, {T}: Tempting Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {G} to end this effect.

All creatures able to block enchanted creature do so.

You have no maximum hand size.

{T}: Add {C}.

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Whenever Tolarian Entrancer becomes blocked by a creature, gain control of that creature at end of combat.

{1}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

(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.

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped.

{T}: Add {G} or {U}.

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

{T}: Add {C}.

{T}, Sacrifice Wasteland: Destroy target nonbasic land.

{T}, Pay 1 life: Add {G} or {U}.

{1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

Prevent all combat damage that would be dealt this turn.

Ferocious -- If you control a creature with power 4 or greater, instead prevent all combat damage that would be dealt this turn by creatures your opponents control.

Search your library for a creature card, reveal it, then shuffle and put the card on top.