Sunstreak Phoenix

Flying
If it's neither day nor night, it becomes day as Sunstreak Phoenix enters.
Whenever day becomes night or night becomes day, you may pay {1}{R}. If you do, return Sunstreak Phoenix from your graveyard to the battlefield tapped.

Magic Online Promos

Innistrad: Double Feature

Innistrad: Midnight Hunt

Innistrad: Midnight Hunt Promos

 Before a player untaps their permanents during the untap step, the game checks to see if the day/night designation should change.

 Day and night are designations that the game itself can have. The game starts as neither. Once the game becomes day (or less commonly, night), the game will be exactly one of them—day or night—going back and forth for the rest of the game.

 For more information about Day and Night and the Daybound and Nightbound abilities, please see the Innistrad: Midnight Hunt Mechanics atricle (https://magic.wizards.com/en/articles/archive/feature/innistrad-midnight-hunt-mechanics-2021-09-02).

 If it is day, and the active player of the previous turn cast no spells during their turn, it becomes night.

 If it is night, and the active player of the previous turn cast two or more spells during their turn, it becomes day.

If a triggered ability triggers whenever day becomes night or night becomes day, it only triggers if it was already either day/night and becomes the other. It does not trigger when the game becomes day or night for the first time.