I was battling a vulture ship, which boarded me since my ship is severely underleveled, and I discarded my Assassin's Strike!! For numbers 1-10, or at least 1-5 on the 'Powers' page, there should be a warning pop-up that asks whether or not you are sure if you want to discard the power. Make it on-and-off switch in the options menu to turn off that function if you want, but I need the warnings!