Japanese translation please
So as has already been said, there is no concept of an "elemental" in traditional Japanese mythology, and moreover, what constitutes an "element" varies from culture to culture. As such, if you wanted to refer to something as an elemental "in Japanese," you would just write it as a katakana gloss, i.e., as エレメンタル ("erementaru"), and you would use the kanji for whatever element you're going to use. So, for "water elemental," I would write 水のエレメンタル ("mizu no erementaru," with "mizu" meaning "water" and "no" as the particle indicating the genitive case).
So if this is what you're looking for, I'll do the rest, but note that "spirit" is a hazy concept, and I would need more details to determine what Japanese word is the closest match.