I know this has been done before but I gotta ask: What're your favorite flavor texts on cards? There are a lot of great ones, both from a cool standpoint (i.e. Invincible Aura) to funny (MANY examples, such as Moon Horn). So to that end, pick one from each civilization!
Here are mine to start:
Fire: Armored Walker Urherion: "The world at peace? I'd rather see the world in pieces."
Nature: Innocent Hunter, Blade of All: "His soul is so pure that anywhere he wanders accepts him as a native son. His infinite destinies lie just over the horizon."
Water: Smile Angler: "I love the ocean! I love fish! I love rocks! I love being an artificial monstrosity constructed by the Cyber Lords! Everything is great!"
Darkness: Snake Attack: "Baraga unsuccessfully gave swords to his army of snakes."
Light: Fu Reill, Seeker of Storms: "The only smoke screen coming from Ballom will be the one billowing off of his smoldering carcass."