In Destiny it used to be that you had 3 upgrade slots for your exotic/legendary gear that needed stuff like Ascendent Energy and Shards. Typically you'd end up with these in your possession by doing the daily heroic, dismantling other similarly rated gear, going on raids, and participating in the public events. End up taking down a raid boss and there was no loot for you? You'd get some ascendant mats. Because of this, inside of Destiny the idea of upgrade materials was completely disappointing for anyone doing raids. After all, who doesn't hope to find some sweet gear for themselves?
So, what was Bungie's solution to this issue? Well, they set it in place with their first expansion, The Dark Below. Basically what they did was make everyone ecstatic to find some upgrade mats, and they did this by making them so much harder to find. You see, the latest legendary raid guns and raid armor need a new currency inside of Destiny if you want to upgrade them. This currency is known as Radiant Energy and Shards, and you can only get them through a raid with just 2 chests and 3 bosses in it. If everything you find was Radiant mats, well you'd end up with around 10ish of these (more or less).
Every single armor piece and gun needs twenty-one Radiant mats in order to upgrade it. Everywhere else that you can find legendary upgrade mats outside of the raid will still be dropping the typical Ascendant Energy, but that isn't at all helpful if you want to be able to upgrade your raid gear.
This lack of upgrade mats will cause some issues in the game. For example, raid armor has stats that are completely random. For example, one piece of chest armor could give you a boost to a specific stat or some mix of the 2, and it can have anywhere between 120-160 points. If you were doing Vault of Glass you could go and upgrade your raid chest piece to boost your preferred stat without much care of replacing that chest piece in the future. This is because there were plenty of upgrade materials to go around. However, that's no longer the case, and if you choose to upgrade anything you better be prepared to stick with it for quite some time. Makes me question much of my time spent searching for legendaries and exotics for guides to post on Power On Pub. Sad.
With the raid, Vault of Glass, everyone playing would complain about never being able to get specific loot drops as a result of the RNG. In the new raid, everyone will complain about being unable to do any upgrades to their new loot because there are no upgrade materials available. Hooray...
