Wow! Thank you for the great feedback something tells me that you're a good game designer.
I might try holding the buff button idea or maybe both and make it do something different. It might be more interesting to have many playstyles.
Showing enemy hp and damage numbers and making the effect look more satisfying could make the game better.
my main problem is that I test the game myself and don't understand what others feel about my game not that I have friends who understand what's wrong with my game anyway
I might take the concept further as one of the classes in my new game