Ethri is a type of energy found in Universe X. It emanates from an entity called Tatsuonga in The Source, and can be found throughout the Lathrym (and even in Ersis) in a number of forms. Arkn channel Ethri in order to practice a type of magic (known as Ethrial Manipulation). Due to its supernatural properties and applications, Ethri is extremely valuable to both the Arkn and the Dekn; competition for Ethri is one of the main causes of the war between the two races.
During the creation of .Mainframe, a rebooted .Reality core was used to create a connection between the base and the universe on top of it. Alongside this, a split in the core was created to allow for the universe to be boxed in. This split core is was taken over by Fab'rasi, and became the Heart of Ethri (commonly known as The Source). Here, Fabras expended the last of its power to create Tatsuonga: the wellspring of all Ethric energy. Arkn, due to the Ethri in their blood, discovered that they could channel Tatsuonga's power directly to practice magic.
The Ethric Mind and the origin of Ethri is known to mortal beings only from scrolls and books written by Jacques. The Source is inaccessible, with no known entrances.
While Ethri itself is a type of energy, it can be be found in liquid, gaseous, and solid form. Liquid Ethri is known as Ethric Fluid.
Super-heated Ethric Fluid will leave behind a crystallized residue that is naturally charged with Ethri. This residue is known as Ethric Crystals. There are three types of Ethric Crystals:
- Naturally Ethric Crystals: These crystals are naturally charged with ethric energy. However, their energy is finite, and cannot be recharged.
- Rethyc Crystals: Naturally empty crystals which can be charged and recharged. Will break after extensive use.
- Nullithic Crystals: Crystals formed from Ethric Volcanoes that cannot hold a charge or be charged.
In addition, ancient super volcanoes of Ethri (such as Mortavrest) can be found. These produce an Ethric Steam that can act as a charge, and even powers some tech in Mistria.
Arkn have Ethric energy contained in their blood (i.e. their blood itself possesses Ethric properties). This gives them a direct connection to the Tatsuonga, and allows them to channel its power naturally. Arkn in the Lathrym practice magic by using Ethri to charge sigils and create auras.
Half-breed Arkn (or Hurn) do not have Ethric in their blood, and must channel Ethri raw. Because of this, they cannot reach the power of a full-blood Arkn, and cannot channel an aura without the use of Rethryc Crystals.
Dekn cannot channel Ethri, and so cannot fully tap into the Tatsuonga. However, they can tap into it mentally enough to draw sigils, which can be charged with Rethyc crystals to be activated (a form of magic known as Siy, which the Arkn also practice).