Transliteration is the act of transcribing words from one writing system to another, and it’s a very complex and imprecise process. The problem is that there are different sets of rules you can use when going from one written language to another, and there’s no absolutely “correct” way to do it, which is why there are 112 perfectly accurate ways to spell Muammar Gaddafi in English (really). Sometimes alternate spellings of foreign names pop up because of a change in politics — as when China switched from the Wade-Giles romanization method to Pinyin, which is why Mao Tse-Tung suddenly changed to Mao Zedong — and other times it’s just fans being silly, like the Minmei-Minmay Spelling Wars that spanned 1980s anime fandom. When Madoka Magika came along, people wondered how to spell the name of everyone’s least favorite magical girl-creating Incubator. Was it Kyubey, which has good balance, or possibly Kyubeh, which creates a pronunciation that’s closer to the Japanese version, or Kyuubey, to represent the long first vowel? Or perhaps QB for brevity’s sake, or Qbey, which appears once in the show? It can be quite difficult, but for our part we generally treat whatever Wikipedia ends up using as “official” (quick is Kyubey in this case). Incidentally if you like, or hate, Kyubey, we have a T-shirt you should see…
Transliterating written words is difficult.