The Creator App that leaked today allows you to get the description for powers in the Creation Crystals! No visual preview, but you can read the info, which allows us to fill in some missing info that's not already on the Wikia site --
http://skylanders.wikia.com/wiki/Elements
Here are the attacks for each element, in the order they are listed, with the descriptions. (
NOTE: You can click the element name for a screenshot of the Elemental Power screen from the Creator app.)
Air:
Storm Cloud - Summon a storm cloud that chases enemies
Twisting Tornadoes - Create powerful tornadoes that track down targets
Shockingly Swift Step - Dash forward, pulling enemies to your starting point and shocking them.
Toucan Zap You - Call in two bird allies that drop lightning explosives.
Dark:
Black Hole - Create black holes that suck enemies in.
Dark Mist - Turn into a dark mist. Stay transformed longer. (I assume that's supposed to be "Hold the button to stay transformed longer.")
Smoke and Shadows - Enhance your attacks with smoke and shadows giving you a damage increase.
Pools of Darkness - Focus your dark energy on a specific location.
Earth:
Earth Shaker - Burrow underground, shaking the ground underneath your enemies.
Crystal Calamity - Summon exploding crystals from deep underground.
Earth Fist - Hit your enemies with earthen uppercuts.
Rhino Beetle - Summon the ancient Rhino Beetle! A Rhino Dive Attack.
Fire:
Burning Dash - Dash with a fire trail.
Meteor Shower - Summon meteors.
Tri Flames - Summon spinning flames.
Explosion - A powerful explosion.
Life:
Vine Bloom - Grow explosive vines.
Wool Over Your Eyes - Turn into a sheep so enemies will not notice you.
Poisonous Pestilence - Creates clouds of poisonous gas.
Flower Power - Grow plants that damage your enemies.
Light:
Rainbow Rampage - Attack your enemies with rainbows.
Flashbang - Toss a blinding orb into the air, damaging and stunning enemies.
Speed of Light - Quickly dash through enemies and send them flying.
Luminous Block - Generate energy cover. If you're hit while pulsing, you create a large explosion of light.
Magic:
Time Bubble - Slow enemies down inside a time bubble.
Trick Teleport - Teleport dash.
Bewildering Blast - Send nearby enemies flying.
Orb Shot - Toss out a set of four magic orbs around you.
Tech:
Tactical Turrets - Create deadly turrets.
Mechanical Microbots - Create microbot helpers that pack a punch.
Motorcycle Mayhem - Summon a sparking gear bike and dash forward.
Mighty Mines - Create proximity mines.
Undead:
Tombstone Timber - Hit your enemies with a tombstone attack.
Last Laugh - Throw laughing skulls at your enemies.
Soul Stealer - Turn the souls of your enemies into health orbs.
Contagion - Release a contagion that spreads around your enemies.
Water:
Wave Push - Summon a tidal wave to keep your foes at bay.
Bubble Bounce - Turn into a bubble and bounce around your enemies.
Ice Block - Create a giant ice block. Push it.
Piranha Pets - Summon hungry piranhas that seek out enemies.