There's an amazing flash online game called Elements. It's a plotless card game with twelve possible elements and very amazing artwork. I want to do a roleplay loosely based around this: with the elements, the creatures, but none of the stats and mana pool and stuff. I've yet to come up with a solid plot, but knowing some of the elements, it would be a battle for the universe.
Here's a list of the elements and a brief description of their powers.
Fire:
Brittle but powerful creatures. Fire destroys, by using spells like Deflagration (destroy a permanent), fireball (does 2 damage plus one for each ten fire mana you have) and immolation (sacrifice a creature for six fire mana plus one for each non-fire mana you have.)
Water:
Good balance between offensive and defensive. Water elementals control ice, alchemy, and aquatic beings. Some of their spells include Ice Bolt, Freeze, and Purify.
Earth:
Very defensive. They have power over mineral, terrestrial, and metal beings. Earth elementals take advantage of special skills, like Burrow (halves damage, cannot be targeted by anything) and shields and hammers.
Air:
Air is the element of freedom. Air elementals have control over flying beings, such as fireflies and Wyrms. They themselves can sprout wings and avoid damage.
Life:
Life elementals have much control over creatures. They rely on primal skills, like Adrenaline (does extra damage each turn, more if the creature is very weak) and poisonous creatures, such as the ill famed Forest Scorpion. Life elementals can use Mitosis to create more creatures as the cost of mana.
Death:
Death is a dark element. They employ vultures, skeletons, parasites, and viruses at their disposal. Death poisons it's enemies, and can even give one of their creatures (or their own!) cancer through the Aflatoxin spell.
Light:
Light is a holy element. Light elementals employ Angels, pegasuses, and crusaders as their creatures. Their helpful spells (such as blessing) do damage to Death and Darkness creatures.
Darkness:
Darkness is a subtle element. They fight with vampires, gargoyles, and mummies. They steal anything from their enemy, even their life. Powerful Darkness elementals can turn the sky black to boost their creatures power.
Entropy:
Entropy is the element of chaos. Entropy elementals work to fuel the death of the universe through disordered spells, like Chaos Seed ( inflict a random spell on a creature) and Mutation (mutate a creature into an Abomination, a random creature with a random ability, or kill it.) Entropy employs odd creatures, like Abominations, Schrodenger's Cat, and Maxwell's Demon at their disposal.
Time:
Time is the element of control. They work to turn the battle in their favor by Reversing Time ( send a creature back to its owners hand. If it a skeleton, it turns into a random creature. If it's a mummy, it turns into a Pharoah.) hastening their card draw (Golden Hourglass) and the odd shield Procrastination. (Creatures are stalled for one turn. Their abilities cannot be used, and they cannot attack until the next turn.)
Aether:
Aether is the element of immaterials. They excell in manipulating dimensions and energy. Aether elementals employ the fewest creatures, and most they call are immaterial. (Immortals, the Phase Dragon, and Psions.)
Gravity:
Gravity is the element of mass. They employ large creatures at their disposal, and excel at manipulating where the enemy attacks. They are infamous for the Armagio (large creature with the Gravity Pull ability, which causes all enemy creatures to attack it instead of the elemental) the Chimera (combine all creatures into one, whic has the power and defense of all added up, gravity pull, and momentum, which Ignores shield effects.) and the Titanium Shield, which pushes large creatures away.
Of course, there are many other skills. Elementals (aka players) can specialize in one, two, or three different elements, but it gets progressively harder the more elements you imploy.
Here's a link to the wiki. I don't require you to read it, or even know the game, but I recommend it.
Link
NOTE: this game also employs the added benefit of "upgraded" cards. I'm on the fence about using these, especially the Shards, as those are extremely OP.