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.

{T}: Add {C}. {T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Whenever a permanent becomes untapped, that permanent's controller mills a card.

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

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

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

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

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.

Flying As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay. Whenever you cast a blue permanent spell, draw a card.

Vigilance When Mirelurk Queen enters the battlefield, target player gets two rad counters. Whenever one or more nonland cards are milled, draw a card, then put a +1/+1 counter on Mirelurk Queen. This ability triggers only once each turn.

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.) Tap four untapped Advisors you control: Target player mills twelve cards. A deck can have any number of cards named Persistent Petitioners.

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.)

The Watcher in the Water enters the battlefield tapped with nine stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.) Whenever you draw a card during an opponent's turn, create a 1/1 blue Tentacle creature token. Whenever a Tentacle you control dies, untap up to one target Kraken and put a stun counter on up to one target nonland permanent.

You may have Copy Enchantment enter the battlefield as a copy of any enchantment on the battlefield.

You may have Estrid's Invocation enter the battlefield as a copy of an enchantment you control, except it has "At the beginning of your upkeep, you may exile this enchantment. If you do, return it to the battlefield under its owner's control."

Enchant player At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn.

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

Creatures don't untap during their controllers' untap steps. Whenever a creature enters the battlefield, untap all creatures.

Whenever an opponent casts a spell, that player mills two cards.

You may have Mirrormade enter the battlefield as a copy of any artifact or enchantment on the battlefield.

At the beginning of your upkeep, scry 1. Whenever you discard a card, each opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

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

Whenever you draw a card, each opponent mills two cards.

As Reflections of Littjara enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process. {5}{U}: Draw a card, then discard a card.

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Counter target spell.

{T}: Add {C}. {2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Halimar Depths enters the battlefield tapped. When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order. {T}: Add {U}.

({T}: Add {U}.)

Lonely Sandbar enters the battlefield tapped. {T}: Add {U}. Cycling {U} ({U}, Discard this card: Draw a card.)

({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.

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.) Target player mills half their library, rounded down.

Draw a card for each Human you control.