Arn't they the same thing? Isn't power just... power, and you are left to your own limits and abilities to control it, lest it controls you? Good and evil, even when given a blanket definition of any kind, or still very complicated things, especially as power escalates. For example (just a general example, not neccesarily 100% historically accurate), it is good to fight the Nazi's because they are trying to take over the world and they were killing minorities, but perhaps that Nazi soldier you gunned down was really a young father looking for work to raise his kids during the depression (and yes, I know Germany was not hit hard by the depression). Sometimes good is pretty absolutely and unquestionable (i.e. curing AIDS), but sometimes good is really evil in disguise (i.e. protesting genetically engineered crops that could save millions or even billions of lives, and even saving those lives would lead to more hunger as the population grows, ect, more harm done).
Power is power, it can do good and bad, soemtimes both at the same time. It's hard to find something to use power for that falls into any absolute (i.e. war may be evil, but it also can kick-start suffering economies and provide jobs to starving people, such as WW2, once again).
