This is something thats kinda bugging me now: if benders can bend fire (lighting included), water (almost all liquids and physical states included), earth (minerals included) and air (and...well...AIR...included), meaning, they bend, in order, an energy, a substance, a solid and gaseous matter, why didnt they invented someone who can bend light, whose properties are balancing between matter and energy? like, dunno, the lightbender creates something like light quick slashes, create a pitch-black darkness to blind their opponents (since darkness is pure absence of light, they would likelly "bend" darkness with blinding properties, like a bender's smokescreen) or even turn themselves and anything desired partially or completly invisible, and masters of lightbending could create more solid things like a lightwall to act as a bulletproof-like glass (so would shatter in strong blows).
This bending could also become usefull for traps or ambushes, like creating small particles of light that would drift around targets unnoticed (or probably mistaken as a flock of fireflys) and with the bender's command, they would "explode" in a strong like like a flashbomb (like a silent and discret flashbomb, the strong light would partially blind the opponents or even knock-out the weakers). Another usefullness would be creating light to...well...light the way, too dark and scary? get a lightbender, he would create light and tadaaaa
Similar to firebending, the user woukld create his own element to bend, in this case, he would have to focus his chi like firebenders focus in their breaths and manifest it as light, loss of focus would cause the light to instantly fade away.
So wacha think about it? seens fair for a bending, as light doestn have that much kinectic force or blasting properties, would be something in the level between air and water, causing less physical damage and better used for escapes, ambushes or long-range, fast attacks.
My martial-art of choice would be Karate (pls, forgive ANY gramatical error in this word), as karate is know for the quickest punches and slashes, fits well with some light coming from the fighter's hands and feets (also, lightbenders could create strong light from their eyes to light something or surprise-blind their foes.
critiques are very welcome ^^ grammar nazis and haters will get a lightbending-fist in their faces .___.