What occurs during the untap step in relation to phasing?

During the untap step, the crucial event related to phasing involves the transitioning of permanents. Phased-out permanents return to the battlefield during the untap step, and phased-in permanents will phase out. This means that permanents which were previously removed from the game due to the phasing effect will once again become part of the game, while those that are active will disappear from gameplay in accordance with their phasing status.

Phasing is a unique mechanic, and its operation is specifically tied to the beginning of the untap step in the turn sequence. During this time, any permanents that are designated to phase into the game do so, thus becoming available again, while those marked to phase out will be temporarily removed. This process does not occur at other times; hence, understanding its occurrence during the untap step is critical for effectively utilizing permanents that interact with phasing mechanics.