The Arkborn are beings of pure, sentient arc energy, that travel the cosmos on an ark filled with circuitry that they inhabit. The Fulminator was taken from the ark by Calus and pledged her allegiance to him in exchange for his promise to leave her kind alone. The councilors, those annoying shield Psions, analyzed the Arkborn and made a special suit that held her together. Her mark was the Statesman Tha'uul.As she fried his mind, she learned of the Stormcallers and wanted to meet them.(I think this is how Calus learned about us) The Arkborn was one of the Shadows that stormed Ghaul's command ship and unleashed her upon him, scattering herself to the wind.