The above Periodic Table of Elements features heroes, villains, monsters, summons, and supporting characters from across the main series - from Final Fantasy I through XIII. Mouse-over for description.
Individuals were associated based on their names and the symbol, usually due to spellings, phonetics, or initials (or out of desperation to best fit someone, anyone).
Even though it was done on a whim, after seeing how it virally spread across the internet, I decided to touch it up, a little bit at a time. I've listed the changes with each incremental version, in case you're interested.
The table was compiled by me, Rafi Hasib, with much of the information and images from The FF Wiki. Characters are property of Square-Enix.