Remember also that the magic isn't something the character can simply decide not to use. Attempting to do this is similar to willing yourself not to see; unless you actually put out your eyes, you won't have much luck. It is part of the character, an integral piece of his makeup. It is a part of them from the day they are born until the day they die. This is not to say a character's affinity is always decided from birth, although this does happen in some cases; however, certain tendencies can be observed early if the character has an inborn affinity for a certain kind of magic. Note that this will also shape their psychology -- those who might be offended at being born tied to a certain type of magic most likely will not be -- the magic is born from their desires and dreams. Also, it's important to note that a character's magic can and sometimes does change as he grows; very few people end up the same person they started as, and sometimes, the changes are drastic enough to change the magic as well.

Another point to make is that whatever magic forms the core concept, the character is not exactly LIMITED to that. They can still cast other forms of magic (an ice queen casting fireballs, for example), but they will be more difficult, and will make the casting of the magics that they are aligned with more difficult as well, lessening that character's affinity. If the differences are extreme enough, and the affinities stretched too far, injury, shock, or death can occur -- often accompanied by some sort of magical backlash.

The changes the magic wreaks upon a character aren't always negative, nor are the always beneficial. The changes bring a character closer to the central idea of the magic they wield. There are three basic types of changes: physical alterations, innate abilities, and mental changes. Those I list here for example purposes are only that -- examples. Use your creativity. The ST's have a right to enforce alterations if they deem it necessary -- all changes, ST or otherwise, will be reviewed by me if there are any disagreements.

• Physical Alterations: Change the wielder's body, anything from a shift in eye or hair color to a loss of mass to rotting of the flesh to idealized perfection of same. I point to Lasander Shadowlove, a Windlord, as an example: he was born blond haired and blue eyed; over the years, both his hair and eyes have become a stormy gray. This is also a reflection of how he tends to focus on the storm aspect of Wind in his magic. Lasander also weighs much less than an ordinary person of his build; about half as much. Lasander is surrounded at all times by a swirling, mild breeze, which can be troublesome in dusty or sandy areas (though he himself is immune to such effects). Physical changes are usually swift to instantaneous, and are usually in response to overuse.
• Innate Abilities: All characters, if their magic is something that could normally harm them, are immune to manifestations of their magic's nature. A Firelord will be immune to fire, including the effects of smoke or heat; the Windlord Lasander is naturally acrobatic and cannot be hurt by falling or similar problems, as well as being immune to sand or dust storms. A WaterLord can breathe under water; a PoisonQueen would be immune to poison -- you get the idea, I am certain.
  While immunities are present from birth, other abilities may develop as the character's magic does. Lasander may speak any language, for example.
• Mental Changes: Slowly being turned into an elemental force or concept includes being brought slowly to accept the mindsets of these concepts or ideas. In a way, it's the mind that shapes the magic, as well as the magic shaping the mind. IceQueens may become more and more removed, distant, and aloof; Firelords will become increasingly reckless and impatient; Windlords, diffident and easygoing; and Earthlords stubborn and thoughtful (maybe even a little slow). Again, don't be limited to the Elementals -- between you, the ST, and even myself if I'm available, I am certain things can be hashed out to mutual accord. Mental changes occur slowly and don't always have a trigger, per se. They're more or less constant if the character doesn't guard against it, like a drift.

Below is a listing of a few different magical abilities and skills that you as the player require knowledge of to play your magically adept character.

Resonance

Power calls to power. When a mage is close to someone whose magic is of the same general type or similar focus as theirs, both mages will experience an increase in power and a decrease in resistance to the magic's effects. They will also feel a pull toward each other, an attraction that is more spiritual than physical. Mages of any type seem to draw others; thus they tend to meet each other more frequently than you might guess.

When mages of opposite types or opposed magics meet, the resonance is slightly different. They do not immediately dislike each other; indeed, there are stories of opposed elementals becoming great friends. However, they will not recieve the boost effect, although each can aid the other in resisting the synergy effect. That is, when both are using the magic, they can use each other to stabilize themselves, letting them push harder than they ordinarily could.

Push

I've mentioned a lot about minor and major effects, but haven't really given you any kind of scale to work with. A good rule of thumb is this: if it's an effect that directly affects a person (not their belongings, but they themselves), it's a major effect.

Generally, anything that would require a major effort to do physically requires the same effort magically. Thus, it's a minor effect to snuff a candle, or even a roomfull of them; calling a storm, on the other hand, is a major effort, no matter how localized it is.

Exceptions to the rule of thumb mentioned above are certain magics involving mental or emotional control. Influences and subtle effects are almost always minor; however, if you overcomplicate things, you may find yourself pushing before you know it. Domination is always a major effect; the more people you affect, the harder it is. If dominating one person involves a push, it's probably a bad idea to try and dominate a whole crowd. ST's and players, some common sense here: if it sounds difficult or complicated, then it probably involves a push.

Backlash

Pushing incurs backlash. The degree of the backlash, and the nature of the effect, depends on the character's magic and on how hard they pushed. This is where things get complicated, because affinity has to be taken into account. Remember that as a person grows closer to his magic, things get easier; effects that once were major may now be minor. I will trust my players and ST's to handle this responsibly in my absence. Backlash effect will be one of those things discussed when characters are discussed with the ST's. Again, I'll give elemental examples in the form of the Shadowloves: Cinder is a fire mage, and burns when he backlashes (that is, burns spontaneously appear on his body); Ciera is ice, and slowly freezes, experiencing hypothermia and stiffness; Lasander's mind breaks down, causing problems concentration and difficulty remaining conscious.

Resistance

Normal, nonmagical humans have an innate resistance to magic, for whatever reason. This is why anything that directly affects them physically requires a push.

If a need to express that resistance comes up, the players can use whatever method they choose to resolve it. If you can't decide, you can always roll a die and the win goes to the higher number.

There is no system for this room, and I'd like it to stay that way. I've found a single die roll to be a very effective and fair method for adjudicating disputes.

More on The Syngery Effect

The closer someone becomes to the nature of his magic, the harder it becomes for him to change further, and the more they must push in order to be further changed. Most mages find a happy medium in this regard. However, the closer you get to that point, the more you WANT to use the magic. It's an addiction.