Ether is a resource that can be used in various aspects of the game, such as crafting, upgrading gear (mostly to L grade) & Dethrone Skills. Now, Ether for the longest time has been sitting in our inventories collecting dust until the " Dethrone: Fire " updated was launched and all of a sudden, it was the most valuable item you could farm due to the requirement in one of the Dethrone Skills.
At first you could use Ether, along with other materials you farm to craft R99 & R110 armors, weapons, brooch jewels and the majority of the items on the craft tab. Then the Dethrone Skills were introduced, which require 400 per day so you can keep leveling one of the skills and finally the L grade upgrades require a substantial amount of ether, north of 100k per item if we are talking about "peripherals", like Circlet, Shirt, Brooch etc, and a little bit less for L grade armor parts.
Well, there are a few ways to get Ether. The most known one is that you get 120 Ether per day per character, from hunting anywhere in the map except Dethrone.
Then you have the in-game adena shop that you can buy 50 per day for 1mil per Ether. There is also the option to buy with gold coins, 10 Ether per gold coin.
For those that are 120+, after the revamp on the daily hunting zones (Pantheon, Jamoa, Fiorens, Crisis), you can get 100 pouches ( Shining Aden Treasure Pouch) that contain Ether, Crystal of Protection, Crystal of Determination and Crystals of Dawn, for the most part the ether is around 90 per day.
So for those 120+ you can estimate around 250 Ether per day.
Additionally, if a compound of armor & accessory soul crystals fails (Eva's, Pa'agrio, Tersi & Masia), you get 1 Ether, so compounding with the character that you need Ether is recommended. Finally, when crafting armor augment stones ( via the craft tab), you get 1 ether per failed attempt, the craft offers a 60/40 chance and it is by far the most accurate in-game success rate. Basically, they players will craft Armor Augment stones and sell them but in the process, make about 40 Ether per batch, since each batch is 100 stones.
One thing is for sure, Ether is not used for anything in the craft tab anymore, for the most part its is used for Dethrone Skills and its not enough. If a player goes by the daily standard, it is 250 Ether using the conventional ways to get it ( 120 from mobs, 50 from Adena store and about 90 from Shining Pouches) but you need 400 for the Dethrone Skills alone.
Crafting Armor Augment stones, costs about 3 billion Adena and you get about 40, but this depends on how much can you wait for those stones to be sold, so you can get your money back.
In the last year, L grade armor and other items have been introduced and are available to obtain for players with the resources to do so. Now as mentioned earlier the requirement there is tens of thousands of Ether for armor pieces and around 105.000 for peripherals like Top Artifact Book, Dragon Rind Shirt etc.
* keep in mind that those numbers might be different between regions, those numbers are for the NA servers.