As the title of this thread suggests, this is where we come to debate the elemental alignments of the SKU cast. For my initial choices, I've limited myself only to those who have Duelled at one point or another, barring Anthy, Akio and Dios. I've presented the choices in the order the characters appear as the series progresses, with the exception of Wakaba (because she's Black Rose and I didn't want to break that bit of continuity).

I've read some analyses, and I've decided to contribute this odd one. Anybody, of course, is welcome to debate my choices, offer alternative reasons for my choices or divine choices for other cast members. If you plan to contribute, be aware that I have a different way of seeing the world...rather very much like an RPG, in fact. I'll give a brief listing of the seven elements I've chosen to employ in quick synopses of the characters who have played a part in Akio's little game, along with the common attributes I associate with them. Remember that nobody's right nor wrong in what they choose, so don't insult somebody's opionions. After all, these are only my opinions, and I'm always willing to see what people can come up with using my various frameworks...

~~~The Elements~~~
Fire: The element of fire is associated with passion, dedication and oftentimes destruction. It can be associated with life and death themselves. It is sometimes thought of as the element associated with intelligence.
Water: The element of water is associated with wisdom, intelligence and sometimes destruction. It can be associated with mothers and other nurturers. It is sometimes thought of as the element associated with age.
Wind: The element of wind is associated with imagination, charisma and oftentimes confusion. It can be associated with artists and creators. It is sometimes thought of as the element associated with youth.
Earth: The element of earth is associated with steadfastness, willpower and oftentimes stability. It can be associated with judicators and law. It is sometimes thought of as the element associated with tradition.
Light: The element of light is associated with goodwill and compassion. It can be associated with purity and nobility. It is sometimes thought of as the element associated with God and Heaven.
Dark: The element of dark is associated with ill will and brutality. It can be associated with sin and destruction. It is sometimes thought of as the element associated with Satan and Hell.
Clear: The element of clear is associated with the unknown and clouded predictions. It can be associated with those who lack direction. It is sometimes thought of as the element associated with Chaos, Entropy and those who fit the common associations of no other element. Clear is considered the "non-element" by many.

Utena: Earth -- Most people would say she's Light or Fire, but I say she's Earth. Willful to the point of stubborness, she nevertheless knows her ideals and stands firmly by them to the very end.
Anthy: Clear -- Some would say Light; others would say Dark. I say she's Clear, the wildcard element. Anthy can go in any direction elementally, but she seems to like being the ambiguous factor in Akio's little game. Most ambiguity is defined as either chaotic or non-elemental, and Clear is my term for non-elemental. So Clear it is.
Saionji: Fire -- A lot of people would say Fire because of the destructive tendencies, or maybe Dark. I say Fire because of how passionately he believes in his ideals, perhaps almost as much as Utena...just in a different way. The defining factor is the emotion: Utena's firm about hers; Saionji's passionate about his.
Dios: Light -- Light, quite obviously. He is, after all, the matter to Akio's anti-matter. He has a vested interest in rescuing Anthy from her fate, but he can't do that without a foil to act with. He's chosen Utena as his foil for reasons that can be debated until the end of time. Unless, of course, you claim a wizard did it...
Miki: Wind -- Being the artist that he is, many would say Water. I define Water as more of the wizened element, and Wind the artistic one. Miki would be associated with Wind.
Juri: Water -- Hard to pin down, but I'd say Water. Why? Because Water and Wind tend to complement each other, and oftentimes Juri acts as a foil to Miki's judgment.
Nanami: Fire -- Definitely Fire. She's always trying to stop everybody that comes between her and Touga, and like Saionji, she's pretty passionate about her ideals -- that is, what little we see of them unless we look hard enough. Obviously, I'm not really counting the filler episodes.
Touga: Light -- Well-intentioned but power-hungry. I'd say Fire or Dark like most would say about Saionji, but I think Touga's more Light than anything else, his manipulative tendencies notwithstanding. Deep down, he genuinely cares for Utena despite being fed bullshit by Akio.
Akio: Dark -- Dark, without a doubt. He's simply too far gone to be any element besides Dark. Anthy isn't so far gone; that's why I said she was Clear instead of Dark or Light. Perhaps, at one point, Akio had a chance to turn Light, but that was probably centuries ago...
Kanae: Earth -- Earth. She follows tradition to the very letter, and most Earth people pride themselves on their deep-rooted conventions of tradition.
Kozue: Fire -- Probably Fire. She knows what she wants and is willing to do what it takes to achieve her goals. That sort of dedication is one of the hallmarks of Fire people.
Shiori: Wind -- If I were a different man, I'd say Dark. But I know better, and I think Shiori's more Wind than anything else. She has a goal in mind, but doesn't really know how to achieve it or even how to implement a successful plan. She seems to be a dreamer type, which is what a lot of Wind people are.
Tsuwabuki: Water -- Water. He's calculating and wise for his years, knowing more about Nanami's plans and observing more about Ohtori than some of the others who have Duelled.
Wakaba: Earth -- Earth, but for reasons different than Utena's. Instead of knowing her ideals, Wakaba's firmly rooted in practical matters, despite being the series' token genki character. Who says boundless energy and common sense don't mix?
Keiko: Fire -- Fire, mainly because of her devotion to Nanami as a means to her greater devotion, Touga. Not even Aiko and Yuuko exhibit the same drive that Keiko shows.
Mikage: Fire -- Perhaps the hardest to pin down, even harder than Juri. I'm tempted to say Dark, but I don't see Dark fitting Mikage at all. I think Fire, due to his passion for attempting to save Mamiya, even if it is by killing Anthy.