So, the thing the Centaurs of the Xie Li Tribe fear the most is being reincarnated as a horse instead of a centaur in their next life.
However, the Chiyan Tribe is not worried about this at all. Even though in their tribe, two-thirds of the offspring born are also horses, they believe it's because they are half-horse themselves, so giving birth to normal warhorses is entirely normal. Their souls are still sea-dwelling human-faced beasts, and they will be centaurs for generations, so there is no need to worry.
One believes horses came first, then humans. Therefore, they fear becoming horses.
The other believes humans came first, then horses. Thus, they have a completely opposite perspective.
Lanling said, "If I want the Chiyan Tribe to believe that I am their Sea Demon Fire God, what do I need to do?"
He didn't speak of changing the Chiyan Tribe's beliefs, as that is impossible, given that their belief system has persisted for thousands, if not tens of thousands, of years.