FFV - The Pillar of Light - Humour, brightness, light-heartedness, general gameplay.
FFVII - The Pillar of Story - Protagonists, antagonists, notable events, plot.
FFXIV - The Pillar of Adventure - Exploration, fantasy, scale, lore, growth.
FFXV - The Pillar of Darkness - Seriousness, darkness, despair, maturity.

FFI - The Pillar of Anonymity - Hello my name is Fighter and I don't have any personality in the game itself

I suspect III would replace I if only I could bring myself to replay it and get any amount of notable distance into the game... someday!