Read my lips. Ascendant Energy and Shards are the MOST VALUABLE materials in the game. MORE valuable to you than a legendary weapon or armor. You can effectively do the raid WITHOUT legendaries if you've got good rares, and you're high enough level. You cannot---I reapeat, cannot---fully upgrade any exotic or legendary items without shards or energy. In fact the "Unique" weapons the Queen's Emissary unlocks for those who get their reputation up to rank 3 are the equivalent of ANY Legendary weapon....until you start to upgrade them with Ascendent Energy. Once people who have done the VoG and have raid gear...going back in to get shards or energy is the main reason why they keep doing the raid.