Okay last week my friends and I were playing in a 3 person melee. Naturally as in any multiplayer game we play my friend always seeks pretty much entirely to destroy me regardless of who's winning or what the wisest course of action would be while I am trying to be cool with him in hopes that the game won't devolve into another grudge match between us with other players basically just spectating or picking one of us to help. He's playing his signature Targaryen Dragons whilst I am playing my signature Stark kingsguard.

I don't usually comment in the Rules forum, but seeing as I play Dragons quite often in Melee… I couldn't help myself.

In order to trigger Meereen, he has to choose a participating Dragon. That means a challenge already has to have commenced and he has to have declared a Dragon character as a participant.

Also, as a side note, if you bring Meera out of Shadows during the standard Shadows action window, you cannot trigger her Any Phase ability. I know, that's a weird one at first glance, but search the forums here and you'll see that one spelled out better than I could probably do it. You could still bring her out of shadows during the normal Player Actions window BEFORE the first challenge is initiated, however. In most games, the difference will be somewhat insignificant because it will feel the same in real-time play, but in others when other Shadows actions are available, it could make a huge difference.

The shadows framework happens at the beginning of each phase, before any player has an opportunity to take player actions. However, as another poster noted, if you bring Meera out of shadows as a normals shadows action, her ability doesn't trigger. Thus, to use Meera as you want to, you have to bring her out of shadows as an Any Phase player action. That said, you'll still get Meera out before he can protect Balerion with Meereen because Meereen targets a PARTICIPATING dragon; you'll have a player action window to trigger Meera's Any Phase action before he can declare a challenge, regardless of who is first player (but note that if he is first player, he will have the first opportunity for a player action, for what it's worth).

Yep. Looks like, in the heat of the moment, you guys need to look really closely at the triggers for effects. (We all do at one time or another.)

Since Meera's "bring out of Shadows, then blank" effect has an "Any Phase" trigger, you have to use that trigger - as a player action - to get that effect. Bringing her out of Shadows at the beginning of the phase does not use that "Any Phase" trigger (it uses the game's rules mechanic). If you didn't trigger it to bring her out of Shadows, you didn't trigger it to blank anything either.

So, since "Any Phase" and "Challenges" triggers on an effect mean essentially the same thing during the Challenge phase, the two effects have the same general timing. And you are quite correct that the first one has to resolve completely before the second one can be initiated. Short of a "Response" effect that uses either the word "save" or "cancel," there are no interrupts in this game. There are no "stacks" or LIFO chains, either. Once an effect - and effect - is triggered, it has to resolve completely before anything other than a "save" or "cancel" effect can be triggered. That's why being First Player matters so much in this game.

However, as has been pointed out above, you have to pay attention to the whole trigger. Meera and Meereen actually do not have essentially the same timing in the Challenge phase because Meereen, in addition to having the standard "player action" timing of a Challenges/Any Phase effect, has the additional target requirement that it can only work on a character that is currently participating in a challenge. That means there are opportunities outside of a challenge, but still during the Challenge phase, where Meera can be triggered, but Meereen cannot.

End result: Shadows actions come first. No one does anything (although you could bring something other than Meera out if you had it/wanted to). Then, move on to pre-challenge player actions. Meereen cannot be triggered here, no matter who is First Player, because there are no "participating Dragon characters." (No challenge has been initiated yet, so how could there be a participating character?) You bring Meera out of Shadows and blank Balerion. (Note that this doesn't count toward your "one Shadow card" limit because that limit is placed on the beginning-of-phase Shadow actions, not on all effects that might possibly bring a card out of Shadows.) Balerion is blank. Someone initiates a challenge and Balerion attacks or defends. Well, he may be participating, but since his text box is blank, he doesn't have the Dragon trait anymore. So your opponent still can't use Meereen on him.

(I know this is the same answer from above. I just wanted to make sure the detail had been spelled out.)