From Lvl 20 I can choose extra abilities, like whirlwind. It is cool, because You can fight with more than one opponent at one time. However I would like to use it when I need (with stronger opponents). It eats my spirit which isnt so cheap to buy and regeneration takes a lot of time (I'm a warrior).
My suggestion is to add more specialities that drains spirit to the option panel on the battle screen (as multi checkbox)