Sounds very overpowered, but i like the general idea of daily power-ups.
I also think it's not really feasible to do this - what if you lose a fight? Should it just keep attacking the same player anyway? or move on to the next? What if it can't find anyone you aren't mobbed with, or can't find anyone that you can beat?
Maybe something like a power hit button is better? (Like someone suggested earlier) That hits 5 times in one click. Trying to find 5 fights is a lot easier than if you have 200 energy at hand.