"When Revealed: Reveal 2 encounter cards per player, and add them to the staging area." - if one of the 2 cards it is a treachery card (let's say...The Necromancer's Reach), how it should be played? Since there are no exhausted characters...Or how it should be played if are revealead only treachery cards?

You should resolve all cards as normal, including treacheries. Also, I am guessing you DO have some exhausted characters at this point. You have just completed the previous quest card, which means you had some characters committed to the quest... they remain exhausted after questing, so that treachery will still damage them.

OK...thank you!