Defeat Hive Knights and Wizards, then bring proof of their demise to Eris. (25)
“Crota’s soul may be defeated, but his armies remain. See to their extermination.” -Eris
There are numerous ways to get the 25 required kills, the fastest way is to do the Chamber of Night mission and reach the “Find the Chamber” checkpoint. Here you’ll find one Knight and one Wizard. Kill them and the back door opens to reveal three more Knights. Kill them then run back up the steps and leap to your death. Repeat this five times total to get all 25 kills quickly.
“You don’t fear the shadows. Maybe there is still hope for the Light.” -Eris
“The Spawn of Crota’s hold on this land is fragile. His disciples will be forced to fight.”