Androids? Isn't it obvious? SUPER MECHA UPGRADE! Kidding, but I can see some ideas involving alien technology upgrades. You could go with maybe an alien module that basically 'over clocks' your hardware to new and extreme heights, but you start to overheat, making it quite dangerous. Though not too sure how that would tie into your current power level system, might have to think on that one a little more. But that's just one idea to throw out there!