To complete the challenge, you need to make sure that there's multiple people holding the aura. If the same person has it more than once, the Challenge-loot will not be rewarded... Full analysis: http://planetdestiny.com/no-risk-good... The Warpriest fires faster and more enemies spawn, but it's basically the same other than that. Changing up the aura is the biggest thing to remember! Normal Challenge Loot - 310 Artifact - 310 ATK Weapon Hard Challenge Loot - 320 Artifact - 320 ATK Weapon - Emblem Other Loot - One Calcified Fragment - Chance at an Exotic