Animate Spell

Flash
Enchant instant or sorcery spell on the stack
When Animate Spell becomes attached to an instant or sorcery, put that card onto the battlefield under its owner's control. It's a creature in addition to its other types with power and toughness each equal to its converted mana cost.
When Animate Spell leaves the battlefield, enchanted card's owner sacrifices it unless they cast it.

Corrupted Key

As long as Corrupted Key is tapped, creatures you control have menace and deathtouch.

Crow Storm

Create a 1/2 blue Bird creature token with flying named Storm Crow.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Five-Finger Discount

Put target nonland permanent into your hand. You may spend mana as though it were mana of any color the next time you cast that card.

Dimir Signet

As long as X is in X's owner's opponent's hand, X's owner may cast X and activate X's abilities. That opponent can't cast X and plays with their hand revealed.
{U}{B}, {T}: Put X into target opponent's hand.
{3}{U}{B}: You may play a land or cast a spell from the hand X is in. If you cast a spell this way, you cast it without paying its mana cost.

Graveyard Busybody

All graveyards are also your graveyards.
Graveyard Busybody's power and toughness are each equal to the number of cards with flavor text in your graveyards.

Form of the Mulldrifter

When Form of the Mulldrifter enters, draw two cards.
You may cast creature cards from your hand as though they were the card Mulldrifter. (You can still evoke this way. They're Mulldrifters.)

Extract from Darkness

Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.

Enchantmentize

Enchant creature or enchantment
Enchanted permanent is an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

Frogkin Kidnapper

When Frogkin Kidnapper enters, target opponent reveals their hand. Choose a nonland card from it. Ransom that card. (Exile it. Its owner may pay {3} at any time to return it to their hand.)

Island

Phoebe, Head of S.N.E.A.K.

Phoebe, Head of S.N.E.A.K. can't be blocked by creatures with flavor text.
{2}{U}{B}: Phoebe permanently steals target creature's text box. (That creature loses all rules text, flavor text, and watermarks. This creature gains them.)

Xanathar, Guild Kingpin

At the beginning of your upkeep, choose target opponent. Until end of turn, that player can't cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way.

Clocknapper

When Clocknapper enters, choose beginning phase, first main phase, combat phase, postcombat main phase, or ending phase. Steal that phase from target player during their next turn. (That phase occurs as though it's your turn instead.)

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Sword of Dungeons & Dragons

Equipped creature gets +2/+2 and has protection from Rogues and from Clerics.
Whenever equipped creature deals combat damage to a player, create a 4/4 gold Dragon creature token with flying and roll a d20 (a twenty-sided die). If you roll a 20, repeat this process.
Equip {2}

Truss, Chief Engineer

Whenever Truss, Chief Engineer enters or another creature dies, put a hack counter on Truss.
{2}, {T}, Remove X hack counters from Truss: Add or subtract X from a number or number word on target spell or permanent until end of turn. This effect can't reduce a number below 1 or a number word below one.

Very Cryptic Command

Choose two —
• Draw a card from an opponent's library.
• Copy target instant or sorcery spell. You may choose new targets for the copy.
• Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.
• Create a 1/1 colorless Gnome artifact creature token.

Gold Mine

{T}: Add {C}.
Legacy — {T}, Mark one of Gold Mine's unmarked nodes: Add one mana of any color.
☐, ☐, ☐, ☐, ☐

Defective Detective

Defective Detective can't be blocked.
When Defective Detective enters, a person outside the game looks at target opponent's hand and chooses a card from it. That player reveals that card.

Animate Library

Enchant your library
Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it. It's still a library.
If enchanted library would leave the battlefield, exile Animate Library instead.

Extract Brain

Target opponent chooses X cards from their hand. Look at those cards. You may cast a spell from among them without paying its mana cost.

Control Win Condition

This spell can't be countered.
Shroud
Control Win Condition's power and toughness are each equal to the number of turns you've taken this game. (If this is in your deck, please keep track of your turns. This means you, Mark.)

Squidnapper

When Squidnapper enters, gain control of target creature an opponent controls until Squidnapper leaves the battlefield or that player pays the ransom.
Ransom — {6} and 2 life

Over My Dead Bodies

Creature cards in graveyards can attack and block as though they were on the battlefield, can block or be blocked only by creature cards in graveyards, are Zombies in addition to their other types, and have undeathtouch. (If they would deal damage to a creature card, exile that creature card instead.)
Creature cards in your graveyard have haste.

Watermarket

{T}: Add {C}{C}. Spend this mana only to cast spells with watermarks.

Hangman

As Hangman enters, secretly note a word with six to eight letters.
{1}: Target player who doesn't control Hangman guesses the noted word or an unguessed letter in that word. If they guess wrong, put a +1/+1 counter on Hangman. Any player may activate this ability.
When a player guesses the noted word or all of its letters, sacrifice Hangman.

Truth or Dare

Target opponent chooses one —
• Truth — That player plays with their hand revealed for the rest of the game.
• Dare — Mill all but the bottom ten cards of that player's library. (To mill, put the top card of that library into its owner's graveyard.)

Mirrored Lotus

Reflect {0} (As this enters, each opponent may pay {0}. When they do, they create a token copy of this except it lacks this ability.)
{T}, Exile Mirrored Lotus: Add three mana of any one color.

Domesticated Watercourse

Domesticated Watercourse enters tapped.
{T}: Add {U} or {B}.
{U}{B}: Until end of turn, Domesticated Watercourse becomes an Equipment artifact with equip {2}.
Whenever equipped creature deals combat damage to a player, draw a card.

Zyym, Mesmeric Lord

Flying, deathtouch
When Zyym, Mesmeric Lord enters the battlefield, target opponent chooses an order for the cards in their hand, then reveals them one by one until you say stop. That player then discards the most recently revealed card.