Can Esli'an make Bladesinger corrupt if she is played to defend from an opponents hand? Or has the window for him to 'corrupt target unit' already passed since he's already been declared an attacker?

Esli'an : Limit one Hero per zone. Action: When this unit attacks, corrupt target unit in the defending zone.

Bladesinger : Order only. Action: When one of your zones with at least 3 developments is attacked, put this unit into play in that zone from your hand, declared as a defender. Action: If this unit has 2 or less damage on it or assigned to it, return this unit to the top of its owner's deck.

DeFrank said:

According to the FAQ, the zone is considered "attacked" when attackers are declared. So I guess both of these cards have the same trigger. According to my interpretation of the arcane text of the flowchart in the FAQ, it looks like both of these actions would have to be taken "as soon as possible" or they would not be able to be used. Since they trigger at the same time, the players take turns putting actions on the chain. So I would say that the attacker goes first, corrupts someone with Esli'an, then the defender puts the Bladesinger into play, so they could not be corrupted by Esli'an.

I don't think the attacker could pass, then the defender players Bladesinger, then the attacker declares they will use Esli'an's power, since the trigger has not been met since the beginning of the action window.

I see. In this senario Eslian is attacking an empty zone (until Bladesingers is played)

I don't know if this helps, but i n my understanding corruption does not prevent a defending unit from participating in combat. Since Bladesinger enters play "declared as a defender", I think it can participate in combat, corrupted or not.

Ahh I see what you are saying. Makes sense.

Thanks for you input!

Ok, so if he is attacking an empty zone then he cannot use his power at all, then the Bladesinger comes in.

I guess that the question now would be that in ad hocs scenario, bladesinger should be corrupted when it comes in. Would that be the right way to play it or no?

DeFrank said:

There is no situation where Esli'an will corrupt the Bladesinger unless the Bladesinger is already in play when Esli'an attacks. In detail:

You pick a zone and attack with Esli'an. This triggers any card that says "When this zone is attacked" and also triggers Esli'an's ability. So now everyone who has an action that can be used once that trigger goes off HAS to use that abilty now or at the next possible instant. Since Bladesinger and Esli'an both triggered, and they cannot happen simultaneously as the game is turn-based, you as the first player/active player/whatever have to take the first action. You try to use Esli'an, but no one is there in the zone, so he can't target anything. Then the opponent uses the Bladesinger, who comes into play defending and not corrupted.

You might be thinking to yourself "But I can just wait for him to play the Bladesinger and then respond by corrupting with Esli'an". That's not true, you would have to pass your opportunity to take actions that are triggered by him attacking, so you would "miss" the opportunity to use his ability at all since you didn't take his action when it triggered. To make this seemingly tiny point clearer, it's like if something triggers at the start of your turn. You can't just wait until whenever you want, later in the turn, like the battlefield phase, to use it. You have to use it once it triggers (when your turn begins) or you can't use it again until next turn.

Anyway, even if I am wrong and somehow Esli'an can corrupt the Bladesinger, I think In hoc is right, that the guy auto-defends. So he could come into a zone with a Warpstone Excavation, for instance.

Understood. Thanks for putting so much time into explaining it to me.