In a recent game two of my rival houses met on the battlefield, the Lannisters fending off a Greyjoy assault. The Lannister player used his Tyrion card and forced the Greyjoy to chose another leader, Greyjoy then played Aeron Damphair and used his special ability to replay the leader card originally denied by Tyrion's special ability.

Now, yours truly was not a party to this conflict, however, now that the crown yet again rests on its rightful Baratheon head, then I am interested - to keep the peace amongst my subjects of course - in how others might approach the Tyrion-Aeron conflict? I've checked the FAQ but found nothing pointing at this subject.

I can equally see how one could argue that Tyrion barred the card for that conflict and thus that leader cannot be replayed through Aeron, as well as see how one could argue the opposite. What are your thoughts? I'm merely curious in case this coincidence should happen again in a future game.

By the rules as written on both cards, I would say that nothing bares doing this.

In fact, in my opinion, the Greyjoy's card might have been designed specifically as an escape against the Lannister's one.

In terms of which is activated first I would say placement on the Iron Throne should decide

Timofeo said:

Tyrion is always resolved before the opponent's card. The general rule from page 19 is that cards which ignore or cancel the opponent's card are resolved first.

Also, the situation here is that Aeron wasn't even played initially, he is played as a result of resolving Tyrion's card.

Timofeo said:

Aeron was chosen AFTER the ability of Tyrion has been resolved, so Iron Throne does not count.

Besides, Ignore/cancel comes always first…

if the 2nd card chosen by gj allows him to change cards it is another matter. He still has to pay 2 pt for that anyway…

i.e: if Tyrion forbids choosing Mace Tyrell for instance and the player then had to choose Loras, does this mean Loras' ability won't work?

Can someone solve this?

I don't see what the problem is. Just follow what the text on the cards say, there is no need to imply extra powers or rules for the Tyrion card.