These are three youma that serve Zoicite as spies and assassins. Each has a different special ability, and all three appear to have slightly super-human physical capabilities as well. One can create powerful pellet-like explosives, another can create waves which induce vertigo, and the third can elongate her root-like limb and use her nails or 'thorns' to drain the energy of others.
The three combined, while formidible, proved to be notably less powerful than Nephrite.