Rivals of Ixalan

Kitesail Corsair | Creature | Human Pirate | Kitesail Corsair has flying as long as it's attacking. | Greg Opalinski

Silvergill Adept | Creature | Merfolk Wizard | As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}. When Silvergill Adept enters the battlefield, draw a card. | Magali Villeneuve

Sworn Guardian | Creature | Merfolk Warrior | | Sara Winters

Timestream Navigator | Creature | Human Pirate Wizard | Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.) {2}{U}{U}, {T}, Put Timestream Navigator on the bottom of its owner's library: Take an extra turn after this one. Activate only if you have the city's blessing. | Zezhou Chen

Warkite Marauder | Creature | Human Pirate | Flying Whenever Warkite Marauder attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn. | Victor Adame Minguez

Merfolk Mistbinder | Creature | Merfolk Shaman | Other Merfolk you control get +1/+1. | Clint Cearley