CT: Done a bit of thinking. Long ago, Lavos crashed into the planet, causing the extinction of the reptites (with the help of humans) and infused the humans with a little of his power which created magic and controlled the evolution of humans. This leads to the kingdom of Zeal, where Magic was the source of power. But Lavos was a parasite to the planet, a threat to the planet, and was to be eliminated.
And so, the legendary Dragons of the Dragonian emerge and fight back!
FF7: Long ago, a meteor crashed earth causing a great damage to the planet. The planet was able to heal itself after as ages passed, but the meteor began to infect the lifestream (or whatever). "The calamity from the heavens" was called the "Jenova", and was a threat to the planet. The planet created the WEAPONS in order to fight back. xD
Another note: Humans with strong magical powers were linked with Lavos somehow in the kingdom of Zeal. Also, many powerful and magical warriors called SOLDIERS were ALSO infused with Jenova cells.
xD How about it?
Okay, this seems impossible, but if Chrono and FF7 worlds wouldn't have been different then I'd say Lavos and Jenova would ACTUALLY have been one and the same!! xD