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

This land enters tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

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

({T}: Add {U}.)

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

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

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

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

Rivendell enters tapped unless you control a legendary creature. {T}: Add {U}. {1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

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

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

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

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

{T}: Add {U}.

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

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.) Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

Target player mills three cards. Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Whenever you cast a blue spell, target player mills two cards.

Each opponent mills fourteen cards. Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.) When you cycle this card, each opponent mills four cards.

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.

Tap target creature. Its controller mills two cards. That creature doesn't untap during its controller's next untap step. (They put the top two cards of their library into their graveyard.) Draw a card.

Landfall — Whenever a land you control enters, target player mills three cards.

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.) As long as Imperious Mindbreaker is paired with another creature, each of those creatures has "Whenever this creature attacks, each opponent mills cards equal to its toughness."

Flying This creature gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Kicker {3}{U} Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

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

Target opponent mills seven cards.

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

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

{1}, {T}: Any number of target players each mill two cards. (Each of them puts the top two cards of their library into their graveyard.) Exhaust — {2}{U}{U}, {T}: Any number of target players each mill cards equal to the number of cards in their graveyard. (Activate each exhaust ability only once.)

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

When this enchantment enters, draw a card, then discard a card. Whenever you draw a card, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

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

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep. You draw a card at the beginning of the next turn's upkeep.

Counter target spell.

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost. Counter target spell.

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

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

Counter target spell. Draw a card, then discard a card.

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity. Equip commander {3} Equip {5}

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

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Return all attacking creatures to their owner's hand.

{T}, Sacrifice this artifact: Exile target player's graveyard.

Instant and sorcery spells you cast cost {1} less to cast. Whenever you cast an instant or sorcery spell, draw a card.

Draw three cards, then put two cards from your hand on top of your library in any order.

Flying Whenever an opponent draws a card, you may draw two cards.

Enchant player Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Target creature gets -1/-0 until end of turn. Draw a card.

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}.

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

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

Target player mills two cards. Draw a card.

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.) Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards. Equip {2}