I was just confused about the new Dormant rules. If a dormant card is attached to a story and a player wins that story card, does the dormant card attached come into play under the winner's control, even if that player didn't attach the Dormant card to the story, or does it come into play under the control of the player that attached it? I assume it comes into play under the winning player's control, but the new rules don't clearly specify this.

Only the player who attached the Dormant card can choose to play it. Here's the Dormant rules text:

“During your operations phase, as a standard player action you may pay X to attach a card with the Dormant keyword facedown to a story as a Dormant card. X is the number of success tokens you have at that story. Limit 1 per story per turn. When that story is won, you may play that card reducing its cost to 0. Dormant cards are considered ‘in play’ but do not count as Attachment support cards.”

Note that 'your' and 'you' always refer to the same player.

Thanks. So it seems the Dormant rules can lead to a new strategy: a player may play a Dormant card at a story where he/she has no success tokens but his/her opponent does (and thereby pay 0 to play the Dormant card). The opponent may need to change strategy and focus on a different story to prevent the Dormant card from coming into play.

I also have some questions:

1. I think story effect will be resolved first, and then play Dormant card. Is it correct?
2. Does Dormant card can be destroyed or sacrificed? Which type the Dormant card is?

I also have some questions:

1. I think story effect will be resolved first, and then play Dormant card. Is it correct?

2. Does Dormant card can be destroyed or sacrificed? Which type the Dormant card is?

1. I'm not 100% sure, but I think so, yes. It makes the most sense to me.

2. It's difficult to affect a Dormant card with other effects because it is completely undefined before it is revealed/played. It doesn't have a card type, name, faction, cost or anything else of the kind, so only effects targeting any kind of card can work; one example would be "Frozen Time".

Edit: There's a similar discussion over at CardGameDB, including a comment that "Frozen Time" would 'fall off' when the Dormant card is played:

http://www.cardgamedb.com/forums/index.php?/topic/17977-dormant-vs-heart-of-the-labyrinth/

Thanks. So it seems the Dormant rules can lead to a new strategy: a player may play a Dormant card at a story where he/she has no success tokens but his/her opponent does (and thereby pay 0 to play the Dormant card). The opponent may need to change strategy and focus on a different story to prevent the Dormant card from coming into play.

Exactly! I think it's rather cool. A pity that only the Cthulhu faction has them (at least for now).