The Iname, or Anti-Life, were the enemy of the Ancients, and fought for twenty-five or thirty-five thousand years during Antiquity. Ryoga is thought to be the very last surviving Iname; Nadel is the penultimate. At the beginning of the Roads War, it is believed, Iname numbered in the hundreds of trillions.
Nothing at all is known for certain about the Iname. Whether they were flesh and blood or needed to eat and sleep is a mystery. However, it is believed they share a common pool of "life force", and that killing one would only extend the lives (and physical prowess) of the others.
The Iname also share a singular will, such that when a decision was made, all co-operated therein, as a single body. The Iname used this will to wipe out all life, for which the Ancients fought them.
The Iname were HIGHLY technologically advanced, even more so than the Ancients. They possesed zero-point power generation and built multi-spatial weapons.
The Iname also had a magic all their own. Its exact nature remains a mystery, but it was powerful enough that even when the Ancients gained an enormous numerical advantage, the Iname were able to hold their own.