Did the Cetra invent magic? Why was Meteor created?

[Ashoka]

My friend is playing through the game and had the following question, which I wasn't quite sure of the answer to, so I thought I'd ask here:

Did the Cetra invent magic, or did they gain this knowledge from elsewhere? If you did invent it, why would they make Meteor to destroy the planet? If they gained this knowledge from elsewhere, from who, and also still why did they make a magic that destroys the planet?

[Gordon Cole]

This is how i always read it.

The Cetra lived almost symbiotically with the planet. The life stream naturally makes materia but I would say that the Cetra knew how to harness it if they ever needed it.

The walls of the "temple of the ancients" show the story of the alien Jenova hitting the planet on a meteor. The Cetra made a specific point to show this in the temple leading up to the black materia.

Jenova corrupted the Cetra turning them into monsters and tainted the lifestream creating the black materia.

After the Cetra froze Jenova in the northern cave they locked the black materia away within the temple of the ancients and booby trapped the temple to collapse when the materia was taken.

The planet created the WEAPONS to defend the planet which awoken when the black materia is used in the game. The planet also made white materia which communicates with the planet to summon Holy when the planet/life is in imminent danger.

Regardless if they made it or not they certainly knew the dangers of the powers it could bring and collectively banished it.

I wouldn't say they invented magic but they understood the planet/lifestream compared to the world/people in the events of FF7.

So yeah Jenova made it not the Cetra

[Darkling]

IIRC Yuffie says on the airship something like, "Isn't it weird that all the materia is used for war?" The implication there is that there should be materia to cook, herd cows, fish, sail, or other mundane tasks, so why isn't there? Why does all materia contain the knowledge of fighting, and nothing else?

I heard that in the Japanese version, someone (maybe Sephiroth during the flashback, or in the Ancient Temple) says that when you use materia you draw knowledge out of the planet, presumably in the form of Mako. Every time you cast a spell, steal something, summon a creature, or use a passive effect you are draining the life force of the planet. Obviously this isn't something that the planet or anything thinking long-term on the planet would want, so I assume it was used sparingly for that reason.

One can look at materia similar to the crystals in previous Final Fantasy games - artifacts which give you the knowledge and expertise of other people's lives, if you put in the work to learn what it teaches you.

With these things considered, we should assume that the planet created materia and gifted it to the Ancients to aid them. Furthermore, they can hear the planet so I assume this conduit they have functions similarly to materia. This meshes with other dialog I vaguely remember which says that the Ancients could use some magical effects without materia. Maybe the process by which they both work is similar.

As for Jenova, I assume that it was out hunting for a big juicy planet to burrow into, so it could suck up all the Mako. The ancient meteor itself may be the remains of a planet Jenova previously parasitized, and the newly summoned meteor may be another related creature or perhaps a Hail Mary play by Jenova put into effect after it started losing to the Ancients.

The whole Meteor -> Shapeshifting Alien Parasite -> Infest local fauna -> Absorb all Mako cycle may be the life cycle of the Jenova creature as a species. Instead of an actual giant space tick/flea like in Chrono Trigger, this one is more subtle.

What does that imply about Jenova itself? Is it a species of interstellar life that moves between the stars and colonizes planets to create abundant life? Does it at some point swarm like bees in an overcrowded beehive to find and colonize other planets? Are they related? Does the planet have previous knowledge of Jenovas?

[Xengre]

We don't know why the Black Materia exists or its origin, but it was likely:
1. Created by the planet just like the White Materia (summons Holy). These are naturally generated materia unlike some of the artifical materia created by Shinra.
2. Comes from the Meteor it summons and somehow arrived (maybe debris seperated at some point or something).
3. Jenova brought it when arriving at the planet as there is the whole riding meteor through cosmos thing though I think this one is a stretch and Jenova likely road a different meteor as there is a wound at North Crater which is far inferior to the monstrosity the Black Materia summons.

It is also very possible Black Materia doesn't summon just a single Meteor, but can summon others as well, but in this case is able to seek a stronger one based on one's power and the one we see is in close enough proximity meeting conditions to be summoned. This fits theory #1 well enough, too.

It is highly unlikely even the Cetra, as capable as they were, could create either Black or White materia.