Whenever a nonartifact permanent enters the battlefield under your control, you may return another permanent you control that shares a permanent type with it to its owner's hand.

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.

Face-down creature spells you cast cost {1} less to cast.

Creature spells you cast cost {2} less to cast. Creatures you control get -1/-1.

Face-down creature spells you cast cost {1} less to cast. {1}{G}: Turn Obscuring Aether face down. (It becomes a 2/2 creature.)

Whenever you cast a creature spell, draw a card.

Whenever a nontoken creature enters the battlefield under your control, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

{1}: The next time you would draw a card this turn, each player returns a permanent they control to its owner's hand instead.

Haste When Craterhoof Behemoth enters the battlefield, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

{T}: Add {C}. {G}{U}, {T}: You may cast spells this turn as though they had flash.

{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.)

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile target player's graveyard. {T}: Add {B}.

({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 one mana of any color in your commander's color identity.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp. {T}: Add {U} or {B}.

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

({T}: Add {G}.)

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

({T}: Add {U}.)

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

{T}, Pay 1 life: Add {B} or {G}. {1}, {T}, Sacrifice Nurturing Peatland: Draw a card.

({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.

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

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

{T}: Add {C}{C}. Activate only if you control five or more lands.

{T}, Pay 1 life: Add {G} or {U}. {1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

({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.

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest. {T}: Add {B} or {G}.

{T}: Add {C}. {T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield. You may cast spells as though they had flash.

Untap all permanents you control during each other player's untap step.

Flash Creature cards you own that aren't on the battlefield have flash. Each opponent can cast spells only any time they could cast a sorcery.

You may cast spells as though they had flash.

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

Counter target noncreature spell.

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

{T}: For each color among permanents you control, add one mana of that color.

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Creatures you control have "{T}: Add one mana of any color."

You may play an additional land on each of your turns.

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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

Return all nonland permanents to their owners' hands. If you return four or more nontoken permanents you control this way, you may put a permanent card from your hand onto the battlefield.

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When Ainok Survivalist is turned face up, destroy target artifact or enchantment an opponent controls.

{T}: Untap target artifact or creature. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Morph {3}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Aphetto Exterminator is turned face up, target creature gets -3/-3 until end of turn.

Whenever a permanent is turned face up, you may draw a card.

Morph {X}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Brine Elemental is turned face up, each opponent skips their next untap step.

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Coral Trickster is turned face up, you may tap or untap target permanent.

Creatures with power less than Den Protector's power can't block it. Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When Den Protector is turned face up, return target card from your graveyard to your hand.

{T}: Counter target spell unless its controller pays {1}. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

{U}, {T}: Target creature attacks target opponent this turn if able. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Echo Tracer is turned face up, return target creature to its owner's hand.

Morph—Return two Islands you control to their owner's hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Fathom Seer is turned face up, draw two cards.

Enchant creature Enchanted creature has deathtouch and indestructible. Morph—Sacrifice another creature. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) As Gift of Doom is turned face up, you may attach it to a creature.

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) Whenever another nontoken creature you control dies, draw a card.

Flying Morph {1}{G}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Icefeather Aven is turned face up, you may return another target creature to its owner's hand.

When Kadena's Silencer is turned face up, counter all abilities your opponents control. Megamorph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Morph {4}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Kheru Spellsnatcher is turned face up, counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may cast that card without paying its mana cost for as long as it remains exiled.

{3}{U}{U}: Turn Mischievous Quanar face down. Morph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Mischievous Quanar is turned face up, copy target instant or sorcery spell. You may choose new targets for that copy.

Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Nantuko Vigilante is turned face up, destroy target artifact or enchantment.

Morph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Riptide Survivor is turned face up, discard two cards, then draw three cards.

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Shaper Parasite is turned face up, target creature gets +2/-2 or -2/+2 until end of turn.

Creatures with power greater than Silumgar Assassin's power can't block it. Megamorph {2}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When Silumgar Assassin is turned face up, destroy target creature with power 3 or less an opponent controls.

Flying Megamorph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When Stratus Dancer is turned face up, counter target instant or sorcery spell.

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) Whenever Unblinking Bleb or another permanent is turned face up, you may scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

As Vesuvan Shapeshifter enters the battlefield or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down." Morph {1}{U}

Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Voidmage Apprentice is turned face up, counter target spell.

{U}{U}, Sacrifice a Wizard: Counter target spell. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

As Ixidron enters the battlefield, turn all other nontoken creatures face down. (They're 2/2 creatures.) Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

At the beginning of your end step, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.) Sacrifice Whisperwood Elemental: Until end of turn, face-up nontoken creatures you control gain "When this creature dies, manifest the top card of your library."