From the video game series known as 'Devil May Cry' everything basically started with great dark knight known as Sparda. Sparda wielded two hand guns which he named, 'Luce and Ombra' - Light and Shadow. Cool, eh?
NOT definitely "LOO-chay"-- Luce is not only the Italian word for light, it is also the French word for light. It would never be pronounced "LOO-chay" in French; "LOOS" would be correct.