Before a player untaps their permanents during the untap step, the game checks to see if the day/night designation should change.
Fangblade Brigand // Fangblade Eviscerator
If it is day, and the active player of the previous turn cast no spells during their turn, it becomes night.
Permanents with daybound and nightbound can't transform via any means other than their daybound and nightbound abilities. Notably, older cards such as Moonmist that instruct a player to transform permanents don't affect permanents with daybound or nightbound.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Vincent Proce
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
