The powerful effects cost a lot of APs, to the point that you may only be able to pull one off by saving several APs from one turn for use in the next. Warrior types (and ranger types) also get various tricks that may not officially be classed as magical but certainly produce effects of similar potency.
Environment-cleaning is generally accomplished with the "Rain" spell or by waiting a short while for the environmental effect to end. (Rain puts out fires in the area - all fires, so you can stop a character from burning, make the lights go out, or safeguard flammable objects.)
