"It's lucky you're here, friend! The torment rifts are spreading, and Nightfall is close! If you're here to help us with the problem, I'll tell you everything you need to know.
What is the nature of this challenge?
"The MargonitePortal Mages are opening Torment rifts between our two worlds. They gather at the rifts to begin the invasion and to open additional portals. Defeat the Portal Mage at each rift to close that rift, and hold them off before they can open more. If you aren't fast enough, they will be able to tear a hole in the fabric of our dimension that we cannot close."
"There are too many demons to defeat. Focus on killing all the demons at a single rift as fast as possible. The sooner you close the rifts, the more time you will have to recover before the demons throw open another. If allow them to open too many rifts, the situation will spiral out of control!"
How do I score points?
"Every monster you kill during this mission will increase your score by 1 point, except for the Portal Mages. Each Portal Mage you kill will close the rift it is standing by [sic] and increase your score by 10 points! You do not need to kill the other creatures surrounding the rift to close it. However, should a new rift open at the same location, additional reinforcements will be summoned with the new rift. So it would be wise to destroy everything around a rift before moving on to the next one!"
What is a Challenge Mission?
"A Challenge Mission is a competition to see who can score the most points. Challenge Missions only end once your party is defeated. You can see how your score ranks against others by visiting the keeper of Records in the Challenge Mission outpost."