Upon the comprehensive, elaborate analysis of all folktales, I favor the folktale, "Princess Kwan-Yin" to the most substantial extent, as it demonstrates the most tangible, relevant overarching theme. Distinguished from the more general themes of the negativities of rapacity and deceitfulness, applicable for the folktales, "The gold giving snake" and "The orphan boy and the mysterious stone" respectively, its theme and concepts concerned is significantly referenced throughout its progression, notably diverging from the "The orphan boy and the mysterious stone", where the theme had been interpreted mainly from applied story continuations, and had not been resolutely highlighted.
Furthermore, the concept of decisioning applicable to the desires of the concerned individual is arguably more impactful and societally relevant than the more rudimentary themes derived from the other folktales.