It's an allegory. Kitsune represent a spiritual person. The number of tails alludes to the stage achieved in the Magnum Opus. In China, Japan and Korea, these have been condensed from 12 to 9. Hence why the highest number of tails for a kitsune is 9. The various steps, taken from Taoism, were listed by HP Lucius Oria in one of his sermons. The Chinese term for kitsune is "Huli jing", while the nine-tailed fox is specifically called "jiuweihu".
An onmyoji is simply a Japanese witch/wizard. Originally, this title was only given to those who had a risen kundalini. Specifically, onmyoji emphasises the mastery over polarities, which is a preliminary step to kundalini ascension, the step when ida and pingala merge.
You can surely discuss these concepts here but keep in mind, like Aquarius stated, that this forum is not based on fiction. We are not a role-playing community.