As Door of Destinies enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies. Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Flash

Flash (You may cast this spell any time you could cast an instant.) Emerge {7}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) Drownyard Behemoth has hexproof as long as it entered the battlefield this turn.

{U}: Giant Crab gains shroud until end of turn. (It can't be the target of spells or abilities.)

{T}: Switch target creature's power and toughness until end of turn.

{2}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

{6}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.) As long as Skittering Crustacean is monstrous, it has hexproof. (It can't be the target of spells or abilities your opponents control.)

Whenever a creature you control deals combat damage to a player, you may draw a card. {1}{U}, {T}: Creatures your opponents control attack this turn if able.

Draw a card. The Ring tempts you.

Draw a card for each Island you control.

Draw a card for each Island you control, then discard two cards.

Look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

When Purple-Crystal Crab dies, draw a card.

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.) Whenever Thassa's Emissary or enchanted creature deals combat damage to a player, draw a card. Enchanted creature gets +3/+3.

You may look at the top card of your library any time. As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library. Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Switch target creature's power and toughness until end of turn. Draw a card.

Enchant creature Enchanted creature can't be blocked. Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

+2: Target creature can't be blocked this turn. −3: Draw two cards. −10: Tap all creatures your opponents control. You take an extra turn after this one.

Enchant creature As long as enchanted creature is attacking alone, it can't be blocked. Enchanted creature has "Whenever this creature deals combat damage to a player, it connives." (Its controller draws a card, then discards a card. If they discarded a nonland card, they put a +1/+1 counter on this creature.)

Devoid (This card has no color.) Target creature can't be blocked this turn. Draw a card.

{T}: Add {C}. {2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

({T}: Add {U}.) Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands. When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

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

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

({T}: Add {U}.)

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

Whenever another snow permanent enters the battlefield under your control, you may have target player mill two cards.

Enchant creature {2}{U}: Untap enchanted creature. Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Spells your opponents cast that target a creature or planeswalker you control cost {2} more to cast. −2: Create a 2/2 blue Wizard creature token. Draw a card, then discard a card.

Flash Indestructible When Mithril Coat enters the battlefield, attach it to target legendary creature you control. Equipped creature has indestructible. Equip {3}

Kicker {1} (You may pay an additional {1} as you cast this spell.) Target creature you control gets +0/+3 until end of turn. If this spell was kicked, that creature also gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

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

Equipped creature gets +1/+1 for each land you control. Equip legendary creature {3} Equip {7}

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

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.) Equipped creature gets +1/+1. Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Equip {3}

As Caged Sun enters the battlefield, choose a color. Creatures you control of the chosen color get +1/+1. Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

As Heraldic Banner enters the battlefield, choose a color. Creatures you control of the chosen color get +1/+0. {T}: Add one mana of the chosen color.

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Blue creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

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

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

Equipped creature gets +1/+1. Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Equip {2}

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.

Counter target spell.

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

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

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.) Channel — {2}{U}, Discard Mirrorshell Crab: Counter target spell or ability unless its controller pays {3}.

Create a 0/3 blue Crab creature token. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")