The Destiny 2 Empty Grief weekly challenge has caused some confusion recently. This seasonal task requires you to complete the Sever (Grief) activity using a Void subclass and only Void, Kinetic, or Stasis weapons. But players have been getting to the end of the mission only to find that the challenge wasn't completed, even though they used the right subclass and weapon elements.
Is it a bug? Kind of. Here's what you need to do in order to complete the weekly Empty Grief challenge and get that season rank XP. If you're aiming for the Season of the Haunted triumph seal, then you might be looking for Calus Bobbleheads, or if you've just started, you might also want to know what Opulent Keys and chests are and how to open them for loot.
Destiny 2 Empty Grief: How to complete the challenge
It's hard to tell if this was intentional or not, but the reason why the challenge isn't completing for some players is because they are picking up the scythe in the final boss encounter. The scythe counts as a Solar weapon, therefore using it means you fail the challenge. When the scythe summons in the final boss, just ignore it, since you don't actually have to pick it up to progress the fight, even if Eris really wants you to.
Equip your Void subclass, and either Void, Kinetic, or Stasis weapons and the challenge will complete just fine. I'm not sure how this affects the challenge, but you should also make sure not to use Solar or Arc finishers, since they do actually count as Arc or Solar kills when you're doing bounties.