Brett sent this one off to a friend of his on a list of kanji that might make a good tattoo, and I have to applaud his judgment. As far as elemental power goes, this is about as awesome as it gets.
1. As fast as the wind, as quiet as the forest, as daring as fire, and as immovable as the mountains
This is a phrase that gets used a lot in conjunction with samurai and battles, as it expresses the versatility to be able to respond appropriately to any situation or opportunity. It can also be used to refer to your business or your personal life as well. It's another one of those that's an abstract concept that works best on its own as a proverb, but if you want to work it into a sentence it often takes 心構え, just like 悪木盗泉.
In business too, you need a heart that's ready to be as fast as the wind, as quiet as the forest, as daring as fire, and as immovable as the mountains.