1. Pokemon Qianmei Fox needs to be upgraded to level 34 to evolve into Kyubi no Youko.
2. A "dark stone" is needed to trigger the special evolution of Kyubi no Youko and make it evolve into a dark Kyubi no Youko. The dark stone is a very rare prop, which can only be obtained through specific activities or exchanges.
3. Upgrade the dark Kyubi no Youko to level 38, and you can evolve into the Phantom of the Dark, the charming fox.