(Work in progress.)
Selas comes from the Greek word for brightness, σέλας(selas).
Rehenwolke comes from the German word for raincloud, regenwolke.
Umrtia comes from the Slovak word for death, úmrtia. Very creative for a necro, I know.
She is also modeled after a sand cherry bush.
Helyge comes from the Welsh word for willow, helyg.
She is also modeled after a weeping willow.
Vlonni came from an Asuran name generator.