Requested by retnahpyrake.
I like the idea of a Sylph of Breath. It has some very interesting potential. That being said, it was a bitch to analyse.
Healing a person's breath could be used in simple terms: helping a person to breathe easier. If a person is having difficulty breathing for any reason - like an asthma or panic attack, or they've had the wind knocked out of them - the Sylph would be able to help them to breathe again. This would be an invaluable resource if you have an asthmatic player, and provided the Sylph liked them, they could be very helpful. This ability probably wouldn't be able to be used for evil purposes, unless the Sylph was helping a bad guy to breathe. This ability could be pushed further though, and for a person who is recently dead and has merely stopped breathing (as opposed to having a serious physical wound), she might be able to heal their breath, thus effectively bringing them back to life (although this might be a tad unrealistic).
By healing a person's freedom, I essentially mean that, if somebody suffered the effect of some kind of mind control, the Sylph would probably be able to restore their mind to its original state, allowing them back their freedom. The only way I can think of that this could be used evilly would be if the mind-controlled person was a bad guy and the Sylph was letting them get away. However, this is much more likely to be used the other way around, with her releasing a teammate of hers from somebody else's control.
By healing movement I mean that essentially, if a person were unable to move for whatever reason - exhaustion, etc. - the Sylph may be able to restore their movement to an extent. I'm not saying that they'd be able to make the disabled walk again (sorry, Tavros) by removing their paralysis, but if, say, a teammate couldn't walk because they were so tired, the Sylph would probably be able to get them going again.
Now, I probably don't mean spirit in the way you think I mean spirit. By spirit, I mean more the psyche, which is often seen as a combination of the mind and soul. By healing a person's spirit, she would probably be able to keep them spiritually as well as mentally stable. Should a person start to lose their faith or sense of being, the Sylph would keep them on the right track and help them to feel less lost.
The Sylph of Breath's abilities are pretty much exclusively benign. There’s almost no way that these could be used for malevolent purposes that I can think of.