Wielding

While the Fay primarily use dust for their enchantment, The Zarth use their life energy to make immediate changes in the world around them. This is called Wielding.

Zarth magic relies on sacrifice, whether self sacrifice, or the sacrifice of others. This makes the "magic" of the Zarth much more mechanical, and focused, than that of the fay. It is also instantaneous, and usually targets a single location. There is very little bleed or spread to Wielding. A Zarth who specializes in Wielding mechanical devices is a Mechanomancer.

Other ideas

Tribal magic, a whole tribe sacrificing to power one Zarth's magic? Drawing on sacrifice along the lines of the Regiments? This way a leader automatically is able to draw from his underlings resources to exert his will directly.