Galdjent Viis and mystel- what's behind those names on the first?

[Vyrerus]

I highly suggest googling Echidna and Greek mythology and the deep darkness and Greek mythology. Also gods cloning themselves is a common theme in Greek mythology too. Atomos is the Greek word for "not-cuttable"--which is how we got the word atom because of the idea that everything can be broken down into its smallest components (atoms) and that small component cannot be destroyed.

I realize that source material for this raid came straight from Final Fantasy III but realize that Final Fantasy III was using Greek mythology source material. A reference of a reference still finds a common base, which is the true source material.

I am versed in Greek Mythology. I said, "Save Echidna" because she doesn't appear in WoD in FFXIV, but in the Void Ark instead. Almost all Final Fantasies have pulled from mythologies from all over the world. It's a lot easier than inventing new monsters off the cuff. The actual relation of FFIII's plot to Greek Myths is pretty much only in monster references.

Also I wouldn't say that Greek gods "cloning" themselves was a common occurrence in the myths. Not sure where you're getting that from.