OKAY GUYS I AM GOING TO SUM UP HOW EVERY FF IS INTERCONNECTED RIGHT FUCKING NOW. PREPARE YOURSELVES.
Okay, so this is how it goes:
(FFI) When Garland was transported into the past by the fiends, the people of that time asked Garland to take them away from the world because of the fiends. Thus with the first killed, Garland was able to find another world (FFIX) that was already habited. With the next fiend killed, Garland created the Lifa Tree to replace the souls, and with the third, he took half the people and hibernated their souls. By the fourth fiend, he knew he posed a threat to the people and went back to the world of FFI. Becoming Chaos, he fought the Warrior of Light. Which upon losing, the fiends go into the future to replace Garland. Garland, who is stranded in the past, dying. Garland heads back to the promise he made on the planet of FFIX. FFI continues into FFV.
(FFV) An ancient evil (from FFI) creates the void, in which they use 12 legendary weapons. Enou is then defeated but the void still continues to exist. They split the crystals which then splits dimensions. Although both worlds are still FFV, one of them grows into FFIV. In which after the events of FFV, the Lunarians debate whether or not they should continue to exist. However, after the events of FFIV, they come to realize they are no better than the humans they were judging over; leaving the world of FFIV to a barren world of FFIII.
Hyne, either created same in power or a Lunarian himself, is entrusted to watch over the hibernating Lunarians. However, every time they have nightmares, monsters become created from it. The first wave of monsters hit the planet below. Hyne takes it upon himself to create people to kill monsters while they entrust another Lunarian, Noah (FFIII), to watch over magic, people and dreams while Hyne slept after the overwhelming task to create people. Hyne becomes notable as the Great Sorcerer Hyne as Noah becomes notable as The Great Arch mage Noah. However, there were too many people when Hyne awoke. The Lunarians didn’t want to repeat FFIV, so the Great Hyne killed the children. The people revolted and defeated Hyne, who split in two to offer his half to the people. This creates a very diluted population of sorceress.
(FFIII) As the people fought over this power, Hein (the stronger half) ends up becoming chancellor in the floating castle of Argus on the floating continent. The whole floating continent was created by Noah for the people that he felt were worthy. Hein is then taken out of Castle Argus for telling people about the crystals that end up disrupting the world. Hein exacts his revenge when he created Castle Hein. Defeated by the Onion Knights, his head vanishes and goes into an abandon shelter that was still in creation. After the events of FFIII, the crystals leave the world and end up on the moon. FFIII continues into FFVIII. Long after the death of Noah (before FFIII), his successor of dreams (Unei) was also dying, but had no one to pass his knowledge to, along with Owen and Desch of the floating continent, which in time sank.
The Lunarians begin a long period of nightmares, which once again started the Lunar Cry, taking down the crystal pillar with it. An unnamed sorceress finds Hein’s head in the shelter and uses his and her power to create Eden. However, Eden was in no match for the crystal pillar, thusly destroying Centra. Long after the events of FFVIII, the people use Eden to travel space to find another habitable planet, away from the Lunar Cry. Taking the name Centra and continue to follow the tradition of sorceress and knight. They finally come to a world of FFX, in which their tradition becomes summoner and guardian. They bring their technology with them, but in the new world, this escalates in a world war. The war ensued and a summoner (sorcerer) named Yu-Yevon creates Sin (Aeon/GF) that he becomes one with (junctions). Yu-Yevon, along with Sin, are defeated and Shinra, an Al Bhed, creates a way to extract life energy by using the Venegun.
In their time, they were unable to create a working process, and take (I’m still showing a map of FFVII and FFX because I don’t think they left) this process with them to another planet. This creates the ShinRa organization in FFVII. After a mistranslation over 2000+ years, the ancients were known later as Cetra. And after a devastating parasitic meteor hit (Jenova), the world regrouped itself afterwards and after the devastation of a later incident. The ShinRa company still looks for a promised land and travel space once again. This time, after/before 3 gods were battling each other, they came across the planet of FFVI. The military force of ShinRa takes control and creates an empire. The military doesn’t understand how to work the mako extractor and aims at a more easier goal of using Espers from that world.
FFII, Tactics, Tactics Advanced and XII develop on their own.
Enjoy your epiphonies.