Board Thread:Wikia Discussion/@comment-749631-20170531082526/@comment-5314514-20170806002849

Despite the contrasting theme, Riku used Schwarz as the name base but "humanized" the word, not shorten it. The reason he changed her name choice is to make it sound less suspicious when she encountered other humans, not for symbolism. In addition, the english translation for the light novel has it as "Shuvi." In this wiki, we consider the closest source to the writer as the canon for spelling and plot. Therefore, the ln translations would be closer to the writer's intent than the movie and anime.