Well the first challenge mode dropped this morning during the reset. Be prepared to be challenged! (It's not really a challenge but easy way for 320 gear)
- more ads, that spawn faster;
- brand holder must change
- deaths/wipes apparently don't matter.
the rewards seem to be:
- Calcified fragment
- Emblem
- 310 artifact (NM drop), 320 artifact (HM drop)
- Max light weapon drop (310 for NM drop, 320 for HM drop)
- as usual, you can get NM and HM drops simultaneously
Interestingly, if you already killed him a chest spawns to give you the extra loot.