Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value. Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.) When you cycle Shark Typhoon, create an X/X blue Shark creature token with flying.

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

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.) Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Destroy target creature if it has mana value 2 or less. Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell and you may choose a new target for the copy.) Counter target spell unless its controller pays {2}.

Look at the top X cards of your library, where X is the amount of mana spent to cast this spell. Put two of them into your hand and the rest on the bottom of your library in a random order. Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Counter target noncreature spell.

Choose one — • Each opponent sacrifices a nontoken creature. • Each opponent sacrifices a creature token. • Each opponent sacrifices a planeswalker.

Counter target spell. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Castle Vantress enters the battlefield tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

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

({T}: Add {U} or {B}.) Fetid Pools enters the battlefield tapped. Cycling {2} ({2}, Discard this card: 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.

{T}: Add {C}. {2}, {T}: Each player draws a card, then discards a card.

If you control two or more other lands, Hall of Storm Giants enters the battlefield tapped. {T}: Add {U}. {5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

({T}: Add {U}.)

{T}: Add {C}. {T}: Add one mana of any color. Activate only if Mirrex entered the battlefield this turn. {3}, {T}: Create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block." (Players dealt combat damage by it also get a poison counter.)

Restless Reef enters the battlefield tapped. {T}: Add {U} or {B}. {2}{U}{B}: Until end of turn, Restless Reef becomes a 4/4 blue and black Shark creature with deathtouch. It's still a land. Whenever Restless Reef attacks, target player mills four cards.

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands. {T}: Add {U} or {B}.

({T}: Add {B}.)

+1: Create a 2/3 blue and black Nightmare creature token with "Whenever this creature attacks or blocks, each opponent exiles the top two cards of their library." −3: Return target nonland permanent to its owner's hand, then that player exiles a card from their hand. −7: You may cast up to three spells from among face-up cards your opponents own from exile without paying their mana costs.

If you would pay life while your library has at least that many cards in it, exile that many cards from the top of your library instead. +1: Look at the top two cards of your library. Exile one of them and put the other into your hand. −2: Create two 1/1 black Nightmare creature tokens with "At the beginning of combat on your turn, if a card was put into exile this turn, put a +1/+1 counter on this creature." −7: Target player exiles the top X cards of their library, where X is the total mana value of cards you own in exile.

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

As an additional cost to cast this spell, you may collect evidence 6. Destroy all creatures. If evidence was collected, exile a card from an opponent's graveyard. Then search its owner's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Choose odd or even. Exile each creature with mana value of the chosen quality. (Zero is even.)