Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Whenever a permanent enters the battlefield tapped and under your control, untap it.

For each opponent, gain control of target permanent that player controls.

Boseiju, Who Shelters All enters the battlefield tapped.

{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)

Return target permanent to its owner's hand.

Coral Atoll enters the battlefield tapped.

When Coral Atoll enters the battlefield, sacrifice it unless you return an untapped Island you control to its owner's hand.

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

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.")

Whenever an opponent casts a spell, counter that spell and put a depletion counter on Decree of Silence. If there are three or more depletion counters on Decree of Silence, sacrifice it.

Cycling {4}{U}{U} ({4}{U}{U}, Discard this card: Draw a card.)

When you cycle Decree of Silence, you may counter target spell.

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.

Tap all creatures.

Flying

Whenever the fourth spell of a turn is cast, flip Erayo, Soratami Ascendant.

Whenever an opponent casts their first spell each turn, counter that spell.

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

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

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.

Flying

{2}, Return a land you control to its owner's hand: Tap target land.

{U}{U}, Return two Islands you control to their owner's hand: Return target creature to its owner's hand.

You may discard an Island card and another card rather than pay this spell's mana cost.

Counter target spell.

Buyback--Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)

Counter target spell.

{T}: Add {C}.

{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.

Draw two cards.

Landfall -- Whenever a land enters the battlefield under your control, target player mills three cards.

({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}.)

({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}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

+2: Each player draws a card.

-1: Target player draws a card.

-10: Target player mills twenty cards.

+1: Until your next turn, whenever a creature an opponent controls attacks, it gets -1/-0 until end of turn.

-2: Reveal the top three cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other on the bottom of your library in any order.

-8: For each player, search that player's library for a nonland card and exile it, then that player shuffles. You may cast those cards without paying their mana costs.

+1: Draw a card. Target player mills a card.

0: Target player mills ten cards.

-7: Any number of target players each draw twenty cards.

+1: Look at the top two cards of your library. Put one of them into your graveyard.

-3: Return another target nonland permanent to its owner's hand.

-8: Each player shuffles their hand and graveyard into their library. You draw seven cards.

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.

You have no maximum hand size.

If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

All creatures get -X/-0, where X is the number of cards in your hand.

Flying

{1}, Return a land you control to its owner's hand: Create a 1/1 blue Illusion creature token with flying.

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)

{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

{T}: Add {C}.

{2}, {T}: Each player draws a card.

{T}: Add {U}.

{U}, {T}: Untap target legendary permanent.

Flying

{2}, Return a land you control to its owner's hand: Target land becomes the basic land type of your choice until end of turn.

({T}: Add {U}.)

Moonring Island enters the battlefield tapped.

{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

{T}: Add {C}.

{4}, {T}: Exile target attacking creature an opponent controls. At the beginning of the next end step, return it to the battlefield tapped under its owner's control.

{T}: Add {C}.

{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Flying

{2}, Return a land you control to its owner's hand: Untap target land.

Flying

{2}, Return a land you control to its owner's hand: Target creature gets -X/-0 until end of turn, where X is the number of cards in your hand.

{T}: Add {U}.

{1}: Return Oboro, Palace in the Clouds to its owner's hand.

Whenever a player puts a nontoken creature onto the battlefield, that player returns a land they control to its owner's hand.

Moonfolk offering (You may cast this card any time you could cast an instant by sacrificing a Moonfolk and paying the difference in mana costs between this and the sacrificed Moonfolk. Mana cost includes color.)

Flying

{1}: Put up to two land cards from your hand onto the battlefield tapped.

Flash

This spell can't be countered.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Return three lands you control to their owner's hand: Return Pearl Lake Ancient to its owner's hand.

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.

Whenever you draw a card, each opponent loses 1 life.

{T}: Target player exiles a card from their graveyard.

{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

You have no maximum hand size.

{T}: Add {C}.

Kicker {5} (You may pay an additional {5} as you cast this spell.)

Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Flying

Landfall -- Whenever a land enters the battlefield under your control, you may gain control of target creature for as long as you control Roil Elemental.

Blue spells you cast cost {1} less to cast.

When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

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

Flying

Soramaro, First to Dream's power and toughness are each equal to the number of cards in your hand.

{4}, Return a land you control to its owner's hand: Draw a card.

Flying

{2}, Return a land you control to its owner's hand: Draw a card, then discard a card.

Flying

{2}, Return a land you control to its owner's hand: Target player mills two cards.

Flying

{2}, Return a land you control to its owner's hand: Target creature with power 2 or less can't be blocked this turn.

Flying

{3}, Return three lands you control to their owner's hand: Return target creature to its owner's hand.

Flying

{3}, Return a land you control to its owner's hand: Target creature you control gains shroud until end of turn. (It can't be the target of spells or abilities.)

Flying

{3}, Return a land you control to its owner's hand: Counter target spell unless its controller pays {3}.

Flying

{4}, Return two lands you control to their owner's hand: Discard all the cards in your hand, then draw that many cards.

You have no maximum hand size.

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may play it without paying its mana cost for as long as it remains exiled. (If it has X in its mana cost, X is 0.)

When a player casts a spell, sacrifice Standstill. If you do, each of that player's opponents draws three cards.

Players skip their untap steps.

At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

All lands are Islands in addition to their other types.

Creatures without flying or islandwalk can't attack.

{T}: Add {C}.

{T}, Sacrifice Strip Mine: Destroy target land.

+1: Tap target permanent. It doesn't untap during its controller's next untap step.

-2: Draw a card for each tapped creature target player controls.

-8: You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand."

Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)

Teferi's Isle enters the battlefield tapped.

{T}: Add {U}{U}.

+1: Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

-1: Untap up to four target permanents.

-10: You get an emblem with "You may activate loyalty abilities of planeswalkers you control on any player's turn any time you could cast an instant."

Teferi, Temporal Archmage can be your commander.

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

Indestructible

As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

At the beginning of your upkeep, scry 1.

{1}{U}: Target creature you control can't be blocked this turn.

{T}: Add {C}.

{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

You may return three Islands you control to their owner's hand rather than pay this spell's mana cost.

Counter target spell.

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Flying

{2}, Return two lands you control to their owner's hand: Copy target instant or sorcery spell. You may choose new targets for the copy.

You may have Vesuva enter the battlefield tapped as a copy of any land on the battlefield.

{T}: Add {C}.

{2}, {T}: You may cast creature spells this turn as though they had flash.