Inza is apparently so cursed that her true form is that of a shadow:
nza's beauty hides a heart of darkness, however. Although she prefers to maintain her human form whenever possible, her true form is a seething, formless wave of semi-liquid shadow. All that remains of Inza are her bright green eyes, glinting out from the darkness. lnza must focus to retain her humanity. She visibly darkens when angered, and her blood is inky black.
-- Ravenloft Gazetteer Volume IV, p156