The quest reads : Forced: At the end of the staging step, reveal the top X cards of the encounter deck, adding all enemies to the staging area. Discard the other revealed cards without resolving them. X is the number of players.

ok, so that maybe is a stupid question, but we have to reveal X enemies only once right?

it doesnt say at the end of each staging step.. so i guess we have to do it only on the end of the first staging step and not in the ones that will follow ?

That's a continually active effect, and the text of such a card will continue to be active every round as long as the card as in play. So any time you reach "the end of the staging step," the Forced effect triggers. This will trigger every round!

oh i see, thx for the answer