I ran into this question from players playing EDH in between rounds at the prerelease this weekend.

AP has moved into her second main phase. After looking at her hand, she declares, “end my turn.” NAP says, “At the end of your main phase, I cast Jin-Gitaxias.” The question that was asked is if AP has the chance to then cast Wrath of God to destroy her opponent's Jin-Gitaxias. My understanding is that she cannot. She has already declared that she was ending her main phase and that players can respond with instants or cards with flash, but she cannot back up to the point of being able to cast sorceries again. This is a discussion I have had with multiple judges who have been split in their judgement.

NAP should probably have been more accurate with their statement, if they didn't want AP to regain priority in their main phase.

"During your end phase, I cast Jin-Gitaxias, Core Augur“ would clearly occur after the main phase, and before the Cleanup step in End Phase. That might have the desired result, of wiping out AP's hand in their Cleanup step… or AP might have an Instant to deal with J-G, Hand Eater.

However, what was said was clear, even if not what NAP really wanted: ”At the end of your main phase". That means that, once J-G, Major Annoyance resolves, AP will again have priority during his or her main phase.

Thanks! - Scott Marshall, L5, Denver; Judge Forums NetRep