Emperor Di Ming did not extend any invitation to the Rakshasa King, Ling Sha King, Di E King, or Tian Nu Wang.
In fact, to some extent, there was never a complete unification between the Demon Alliance and Na Xue.
Although the four Demon Kings had expressed their intentions to ally with Princess Na Xue and their willingness to establish the Vampire Demon Race Alliance.
How can one describe this relationship? It is as if certain joint ventures within the country.
Princess Na Xue is like a super powerful company, akin to Volkswagen in Germany. However, after entering the country, due to certain policies, they couldn't establish a wholly-owned company and had to merge with domestic enterprises to form a joint venture, becoming FAW-Volkswagen or SAIC-Volkswagen.
This is destined to be an unequal cooperation, where the other party possesses the technology and controls everything.
