Mystery Skulls Theory (crossposted from Tumblr)

[cal1pso]

Some of the legends say a kitsune gains a tail every hundred years.
Another myth says that a kitsune gains all nine tails when they reach
nine hundred years old. When a kitsune becomes a nine-tail, their fur
becomes either silver, white, or gold.

A kitsune may gain a tail for bringing honour to their family and clan, or could lose one for breaking kitsune law

Given to Bai Mianxi by Luna, the Heavenly Mandates are the laws of
Kitsune society. It consists of four obligations, four bans and an
absolution.

I command you to destroy that which harms Gaia.
I command you to aid your brothers, your sisters, and that which serves Gaia.
I command you to revere Your Mother, Myself, your Aunts, your Uncles, and Our Favored Servants.
I command you to keep your duty first in your heart, and to listen for my teachings.
I forbid you to exterminate the humans.

I forbid you to make war on your brothers and sisters.
I forbid you to break your word.
I forbid you to commit suicide for reasons of honor.
I free you to do anything else necessary to achieve our goals.