Let me tell you something. You absolutely ROCK!
I tried your solution exactly as you proposed it, and everything works wonder! Now both effects are implemented nicely into the game, and my code is cleaner and shorter than it was before, also thanks to the advice of other people in the first replies, which also have my gratitude. But best thing is that I learned a lot.
Thanks for your kind words about my game. If you like the mobile version, chances are you will like the PC version I'm working on. The mana bar is now placed in the center bottom, but it's not as important as it won't be touch-based anymore and you shouldn't have your thumb before the screen. But I keep your feedback in mind for the next mobile update.