I would have said Fiend. Demon is demonic, Goddess is angelic, and Fiend is... what is he supposed to be? What does he represent if not demonic, since he looks even more unholy than Demon? This makes him so much more mysterious to me.

However, he loses some points for me for using Northern Cross, plus Demon's design is overall cooler in the long run. So I vote Demon.

Demon represents Hell, Fiend represents Purgatory and Goddess represents Heaven. Just like the three first phases of Kefka, each of the Warring Triad represents one of those three places.

In other words, Demon is, well, a demon, Fiend a "fallen angel" so to say, and Goddess is an angel/god

Ah, that makes sense.

I knew the Statue of Gods represented Hell, Purgatory, and Heaven of course. I didn't realize those three did as well.

And at the top you get a mad clown.