What every Final Fantasy game is about.

FF I: A crazy god decides that the world got too boring and that the strong should rule the weak, so he unleashes his minions all over the land in an attempt to bring his new law to fruition.
FF II: A crazy emperor is searching for ultimate power so he sells his soul to the devil (kinda) and becomes a heartless killing machine bent on world destruction.
FF III: A crazy woman goes to cause some mischief and ends up making the life of everyone miserable.
FF IV: A crazy noble knight comes up with a plan to resurrect a deity and change the future of every living being but ends up nearly causing the end of the world.
FF V: A crazy fiend in armor with power over the void had nothing better to do so he embarks on a journey to become a memorable final boss who wants to kill everyone and everything.
FF VI: A crazy clown that enjoys seeing others die acquires magnificent power and uses said power to show just how much swag he has over everyone else by nearly destroying the planet.
FF VII: A crazy white-haired woman man loses his mom and goes hell bent on destroying every living thing because they are sucking the life energy of the planet.
FF VIII: A crazy witch messes with time to obtain ultimate superiority over everyone else and show just how cool her guardian forces are.
FF IX: A crazy teenager with improbable hair manipulates everyone to ultimately rule all the continents by destroying them.
FF X: A crazy swordsmagician reshapes the destiny of humanity when he does a lot of inexplicable things and ends up becoming the harbinger of doom.
FF XI: A crazy being that controls other crazy beings uses his authority to shove his crazyness into lands that are filled with other crazy beings.
FF XII: Five crazy judges pass law on the entire nation and end up becoming villains even though they deny being villains of any kind.
FF XIII: A crazy old man spews nonsense about another crazy entity that can make things but ends up not making anything significant.
FF XIV: A crazy object influences the masses by giving them super powers that are solely meant to fill in the game's true purpose and has no meaning on evilness whatsoever.
FF XV: Possibly another crazy person or creature with some ridiculous plot.

Moral of the story? They're all crazy guys.