It says "Marshalling: Kneel Crawn Son of Calor to choose 1 Clansman card in your discard pile. You may play that card as your next action as if it were in your hand." Now I'm the first player, and I finished marshalling, can I trigger Crawn Son of Calor through player action in my opponent's turn?

My friend tell me no, because player is allowed to play a card just in his marshalling action, no one can play a card after he complete marshalling.

But in my opinion, I just trigger a card effect through an action as usual, even if it is not in my marshalling turn.

Who is right? And why? Thank you.

You're both right.

You're right in that you would be allowed to kneel Crawn, choose a character in your discard pile, and have the option to play it as your next action as if it were in you hand. So you are right in the technical sense: you can trigger Crawn while you are not the active player in Marshalling.

But your friend is right that, when you get to the next action, playing that card "as if it were in your hand" would be illegal since you are not the active player. That means the card is going to stay in your discard pile. So your friend is right in the practical sense: you won't accomplish anything (other than kneeling Crawn) if you trigger Crawn while you are not the active player in Marshalling.

It is true that card text trumps basic rules, but only when the card text directly contradicts the rules. There is nothing in the text "You may play that card as your next action as if it were in your hand" of Crawn's ability that contradicts, directly or otherwise, the basic rule that you can only play non-event cards from your hand while you are the active player in the Marshalling phase.