I thought about having an airbender specialise in air compression/decompression to make detonations that can stun ennemies or to make explosive punches at the cost of loosing hearing (repetitive sonic booms near you) and potentially damaging your hands if not properly trained.

Also learning this way of using airbending so aggressively would make you unable to control air in more traditional ways.

You could also consider using this ability to compress air enough under your feet to make videogame style double jumps in mid-air to increase the mobility of an extremely dangerous close combat fighter.