Ixalan

Arcane Adaptation | Enchantment | | As Arcane Adaptation enters the battlefield, choose a creature type. Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield. | Mark Behm

Daring Saboteur | Creature | Human Pirate | {2}{U}: Daring Saboteur can't be blocked this turn. Whenever Daring Saboteur deals combat damage to a player, you may draw a card. If you do, discard a card. | Victor Adame Minguez

Dreamcaller Siren | Creature | Siren Pirate | Flash Flying Dreamcaller Siren can block only creatures with flying. When Dreamcaller Siren enters the battlefield, if you control another Pirate, tap up to two target nonland permanents. | Eric Deschamps

Entrancing Melody | Sorcery | | Gain control of target creature with mana value X. | Winona Nelson

Fleet Swallower | Creature | Fish | Whenever Fleet Swallower attacks, target player mills half their library, rounded up. | Tomasz Jedruszek

Herald of Secret Streams | Creature | Merfolk Warrior | Creatures you control with +1/+1 counters on them can't be blocked. | Sara Winters

Kopala, Warden of Waves | Legendary Creature | Merfolk Wizard | 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. | Magali Villeneuve

River's Rebuke | Sorcery | | Return all nonland permanents target player controls to their owner's hand. | Raymond Swanland

Search for Azcanta // Azcanta, the Sunken Ruin | Legendary Enchantment // Legendary Land | | At the beginning of your upkeep, surveil 1. Then if you have seven or more cards in your graveyard, you may transform Search for Azcanta. (Look at the top card of your library. You may put that card into your graveyard.) // (Transforms from Search for Azcanta.) {T}: Add {U}. {2}{U}, {T}: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in any order. | Magali Villeneuve

Spell Swindle | Instant | | Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.") | Victor Adame Minguez

Hostage Taker | Creature | Human Pirate | When Hostage Taker enters the battlefield, exile another target creature or artifact until Hostage Taker leaves the battlefield. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell. | Wayne Reynolds

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

Glacial Fortress | Land | | Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island. {T}: Add {W} or {U}. | James Paick