Predictions: Whitebeard's War

[Augury]

I don't think it's happened yet (in a serious fight)

Logia we've seen:
Smoker (smoke logia: win vs. Luffy, draw with Ace, almost drowned vs Crocodile)
Ace (fire logia: draw with Smoker, loss vs. Blackbeard)
Crocodile (sand logia: 2-1 vs. Luffy)
Blackbeard (darkness logia: win vs Ace)
Enel (lightning logia - win vs. Sanji, Ussop, Kamakuri, Gan Fall, Robin, Zoro, Wiper, loss vs. Luffy)
Aokiji (win vs. Luffy)

Zoro's opponents:
Kabaji
Fat & thin cat pair
Mihawk (loss)
Hachi
Igaram + bounty hunters
Mr. 1 (Supa supa fruit - can turn body to steel, paramecia)
Braham
Enel (lightning logia, loss)
Aokiji (ice logia, withdrawn)
Kaku (giraffe zoan)
Ryuuma
Oz, Moria (team fight, got thrashed)

Sanji's opponents:
Pearl, Gin
Kuroobi
Bananadiles :P
Mr. 2
Enel (lightning logia, loss)
Aokiji (ice logia, withdrawn)
Kalifa (awa awa fruit - can produce bubbles - paramecia, loss)
Jyabura (wolf zoan)
Absalom (invisibility - paramecia)
Oz, Moria (team fight, got thrashed)

That's what I can think of for now (small fry omitted). So basically, we've seen a logia user defeated three times - twice by Luffy and once by Blackbeard.

Yeah, I know I didn't have to list it out but I had fun thinking about it :P