Quote from BluurThe idea just hit me: how about everytime he uses an ability, it takes time off his life and the watch slowly cracks each battle
If it does that, won't the watch eventually break, and how will he fix it? If it breaks how will he continue to battle not only in the current one but in any battle afterwards?
His watch could drain his internal energy, causing him to become extremely tired after using it, especially for long durations. Say something like (example) "If he uses his watch for over 10 seconds, he becomes exhausted to the point where he can almost not fight anymore".