Thanks to Squallish for the inspiration.
FFIV: Tellah was also a Lunarian, one who was studying the people on Earth. He forgot due to his amnesia. Hints are his long white hair and purple robe matching the purple tones of FuSoYa, Golbez, and Cecil.
Summoners are the offspring of certain monsters and Lunarians. Meteo can only be cast by Lunarians and their descendants (Golbez, FuSoYa, Tellah and Rydia).
It’s not as far-fetched as it seems. Tellah does have white hair and purple robes like FuSoYa. Like FuSoYa, he’s proficient in both White and Black Magic. It’s not clear how Tellah learned his spells. Tellah could have learned them at Mysidia. But he also could have learned them anywhere, including the moon. It’s not clear how Lunarians learn their spell if they’re not born with it.
We’re not sure how Tellah lost his memory. His amnesia kept him from casting his most powerful spells (which is a narrative plot point and level cap). FuSoYa can cast all White and Black Magic.
There doesn’t seem to be anything preventing a normal human from being able to cast Meteo. As a Black Mage, Palom can cast it. But this assumes that Palom, and his twin sister Porom, are from Earth. For all we know, they could be half-human and half-Lunarian as well. This might explain their aptitude to learn magic at a faster rate than all of the other students. I’m sure they’re the best Mysidia has to offer.
Consider that another human, Lenora, who ironically is a better Sage than her teach Palom, cannot cause Meteor. The powerful sorcerer Golbez can, yet he can also summon monsters. Before our first battle with him, Golbez was able to summon a dragon. Yet Rydia’s Myst Dragon defeats it.
So then is Rydia, like most summoners at the Village of Mist, the offspring of Eidolons and Lunarians?
If we assume only the offspring of Eidolons and Lunarians can summon Eidolons, then Golbez’s mother is an Eidolon. We know only Golbez’s and Cecil’s father was a Lunarian. But then Golbez and Cecil are brothers. So then could Rydia summon Eidolons for being a half-Eidolon herself? And if Golbez can summon Eidolons, does that mean Cecil can as well? Is Cecil half-Eidolon as well as half-Lunarian? Would this make Theodore able to summon as well?
But of course, we know that Cecil and Golbez’s mother is actually just a regular human named Cecilia. But Golbez can learn to summon without being an offspring of an Eidolon. Therefore, having an Eidolon linage isn’t a requirement to summon other Eidolons. In Rydia’s case, it depends on whether they like you or not 🙂
We do not know about Tellah’s origins, so it does lead to the possibility that he could be a Lunarian.