The relation between Dahna and Rena is similar to that of Inferia and Celestia, where they both exist in rather close proximity to each other while knowing about the other world, one world being a much more technologically advanced (Celestia, Rena), while the other being behind (Inferia, Dahna).
Enslaved Dahnans have spirit cores embedded in their hands, similarly to how Desians embed Exspheres into slaves. In both cases it is related to gathering power through unethical means.
At the start her journey with the others, Rinwell hates and is very hostile towards Renans, similarly how it was in the case of Annie Barrs. Both characters start to accept the other side as they experience more things.
Shionne Vymer Imeris Daymore shares many similarities with Estellise Sidos Heurassein, including being a member of high society, a user of potent healing magic artes, and harboring a power that can possibly bring destruction of the world.
While astral energy is the lifeforce of all matter, similarly to the recurring concept of mana, it is most similar to eleth.
The Great Astral Spirit is similar to Fodra Queen in terms of being an entity formed from a massive concentration of astral energy. Both of them also see humans as enemies to their own well-being.
If large amounts of astral energy of a single element are accumulated in a spirit vessel it may result in an elemental spirit's manifestation, like when in Bermia Gorge the large amount of mana drained from experimented people resulted in formation of a spirit-like Wind-elemental entity.
