Played this with my friend and we're both level 30 and finished the adventure. Can we do it again higher level because when host first part again the mobs didn't get stronger. Figured must be able to since see level 150 people.
People usually grind using the Marshlands mission. Usually, a few people stay near the sarcophagus, and repel the enemies there, while the rest each go to one of the portals (alone, preferably), and kills the monsters there, without actually closing the portals.