@Necromancy that idea falls perfectly into one of the Manifestations I had in mind, I would totally accept that idea, for sure, I just need to explain what they are, and with the amount of people showing interest, it looks like I might need to make more.

But, as I promised, I'll give you at least that for now, so, here are the first 4 Manifestations, and a brief description of what it is.

A Manifestation is a person's connection to the Spirit World and they way they can manipulate the Aethr, giving them special abilities in the material plane. They consist of several types of Manifestations, such as: Avatars, Shamans, Aethrmancers, and Geomancers.

Avatars are connected to the Spirit World through what is known as a medium, an item existing in the material plane that has been infused with a being of Aethr, usually a weapon or trinket. The spirit in question is usually a famous warrior or sage, looking to find a way to continue their legacy through an Avatar. The spirit and the Avatar combine energies through the medium, performing spectacular supernatural feats of strength, speed and intellect. 

Shamans enlist the aid of the spirits from the Spirit World, summoning them when they need aid, and the power of the summons vary on their level, and they range simply from being a level 1 spirit to being a level 5 or anywhere in between. Summoning a spirit usually requires a focus, an item used to call them back to the material plane, and can literally be anything, but to bind a spirit to a focus requires great will and concentration, but once bound and summoned, they can be called and expelled to provide their special abilities and skills to the Shaman's arsenal.

Aethrmancers can use their inner reserve of the Aethr to perform supernatural feats, such as summoning fire and creating clones of themselves. This is known simply as magic, and any Aethrmancer with a great amount of Aethr and willpower can cast their magic with ease. However, due to the fact that their surging with the energy of the Spirit World, they are often on the brink of madness- and tearing themselves apart with the power they hold.

Geomancers can manipulate the physical world using the Aethr around them, and can shape the world as they see fit, using a seemingly unlimited well of power, but there is a catch to the use of the power of a Geomancer; they can only create matter, not deteriorate substances as they please. This causes them to be adept healers and witch doctors, as they are usually seen, creating strange and unique brews and extracts, healing wounds, and repairing the land as they see fit.