A bit of brains, but not much.
This is Hill's final assessment.
Glaysia probably used all her brains in her battles of wit and courage against her dad and his followers, which led to her making such a crazy move.
Maybe she thought Lansendel felt lonely here alone, so she specially invited Celene?
This rough and overly primitive Moon Prayer Dance could indeed be sensed by the Goddess of the Silvermoon, and there's a natural reason behind it.
As Toril's Primordial Goddess, the initial faith Celene received originally came from beasts with a hint of intelligence.
The beasts worshipped the moon hoping for better food and longer life, and back then deities were willing to extend their hands to such sincere cries for help.
Take, for example, Shantia.
Those powerful beasts surrounding her were accumulated during that period.
As Toril became more complete, and beasts grew smarter, along with the emergence of various races, rituals gradually turned into ceremonies.
