When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Return target nonland permanent you don't control to its owner's hand. Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

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.

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

As Kindred Discovery enters the battlefield, choose a creature type. Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

Whenever a creature you control deals combat damage to a player, you may draw a card. Cycling {2} ({2}, Discard this card: Draw a card.)

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

When Crystal Grotto enters the battlefield, scry 1. {T}: Add {C}. {1}, {T}: Add one mana of any color.

({T}: Add {U}.)

{T}: Add {C}. {2}, {T}: Scry 1, then you may reveal the top card of your library. If a basic land card is revealed this way, put it onto the battlefield tapped. Activate only if an opponent controls at least two more lands than you.

{T}: Add {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

{T}: Add {U}. Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Path of Ancestry enters the battlefield tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

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

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

When The Grey Havens enters the battlefield, scry 1. {T}: Add {C}. {T}: Add one mana of any color among legendary creature cards in your graveyard.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Urza's Saga gains "{T}: Add {C}." II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'" III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Whenever you draw your second card each turn, create a 2/2 blue Drake creature token with flying. Whenever you draw your fifth card each turn, Alandra, Sky Dreamer and Drakes you control each get +X/+X until end of turn, where X is the number of cards in your hand.

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.) LEVEL 2-3 3/3 Flying LEVEL 4+ 4/4 Flying Other Merfolk creatures you control get +1/+1.

Sacrifice Cursecatcher: Counter target instant or sorcery spell unless its controller pays {1}.

You may cast Harbinger of the Tides as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.) When Harbinger of the Tides enters the battlefield, you may return target tapped creature an opponent controls to its owner's hand.

Creatures you control with +1/+1 counters on them can't be blocked.

Spells your opponents cast that target a Merfolk you control cost {2} more to cast. Abilities your opponents activate that target a Merfolk you control cost {2} more to activate.

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token. Tap seven untapped Merfolk you control: Counter target spell.

Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Protection from red Elemental creatures you control get +1/+1. When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Other Merfolk creatures you control get +1/+1. {T}: Target Merfolk creature can't be blocked this turn.

Flying Whenever Merfolk Windrobber deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.) Sacrifice Merfolk Windrobber: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.

Other Merfolk creatures you control get +1/+1. Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Flying Other Merfolk you control get +1/+0 and have flying. Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Mist-Cloaked Herald can't be blocked.

River Sneak can't be blocked. Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Whenever a Merfolk you control deals combat damage to a player, draw a card.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Merfolk spells and Wizard spells you cast cost {1} less to cast.

Svyelun of Sea and Sky has indestructible as long as you control at least two other Merfolk. Whenever Svyelun attacks, draw a card. Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

When Tempest Caller enters the battlefield, tap all creatures target opponent controls.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.) Flying When Thieving Skydiver enters the battlefield, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.

Kicker {1} (You may pay an additional {1} as you cast this spell.) When Tide Shaper enters the battlefield, if it was kicked, target land becomes an Island for as long as Tide Shaper remains on the battlefield. Tide Shaper gets +1/+1 as long as an opponent controls an Island.

Flash When Tishana's Tidebinder enters the battlefield, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

Triton Shorestalker can't be blocked.

As True-Name Nemesis enters the battlefield, choose a player. True-Name Nemesis has protection from the chosen player.

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.

Nyx Lotus enters the battlefield tapped. {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

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

Imprint — When Semblance Anvil enters the battlefield, you may exile a nonland card from your hand. Spells you cast that share a card type with the exiled card cost {2} less to cast.

Sky Diamond enters the battlefield tapped. {T}: Add {U}.

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

{T}: Add {C}. Put a point counter on Strixhaven Stadium. Whenever a creature deals combat damage to you, remove a point counter from Strixhaven Stadium. Whenever a creature you control deals combat damage to an opponent, put a point counter on Strixhaven Stadium. Then if it has ten or more point counters on it, remove them all and that player loses the game.

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}

Return target nonland permanent to its owner's hand. Then that permanent's controller may sacrifice a land. If the player does, they may copy this spell and may choose a new target for that copy.

Counter target spell.

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

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.) Enchant creature, planeswalker, or Clue Enchanted permanent is a colorless Clue artifact with "{2}, Sacrifice this artifact: Draw a card" and loses all other abilities. (It's no longer a creature or planeswalker.)

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

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying. Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Counter target noncreature spell unless its controller pays {2}.

Enchant land When Spreading Seas enters the battlefield, draw a card. Enchanted land is an Island.

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

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.) Draw a card.

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

{1}, {T}: Exile any number of cards from your hand face down. Put that many cards from the top of your library into your hand. Then look at the exiled cards and put them on top of your library in any order.