See Sephiroth. This is a transliteration—the way a word sounds in one language spelled out in another—of a Hebrew term. In the most common transliteration, the “th” is pronounced with a hard “t” followed by a short breath, not like the “th” in the English word “the” (phonetically, the “th” in “the” is called a “fricative”). This is not clear in the archaic “Sephiroth” spelling, leading many people, untrained in Hebrew, to end the word with the fricative, so it sounds (incorrectly) like "seh-fear-oath." The spelling “Sephiroht” makes the correct pronunciation, “seh-fear-oat,” more obvious.