Mystics are a magic class that uses their arsenal of wood skills as well as a set of summons (the summons will let you tap into other elements, such as metal and fire) and plants to attack, and their healing and defense skills to help themselves and their allies survive. Instead of taming their pets like the venomancer, the mystic has a fixed list of summons which they can summon using their skills. The mystics can also summon plants, which then stay where summoned and affect nearby targets automatically. Each of the summoned plants is used for a special purpose, from delivering damage, to AoE debuffs, to healing teammates. Even though the mystic is a good solo class thanks to their summons, they're good team players as well, due to their various healing and support skills.

Source: PWI Official Wiki