[Akito Kinomoto]

I generally have low tolerance for the instances where the author introduces a character so powerful to the point where they can only be defeated by some illness. There are times when there is adequate set-up for this so as not to appear like a complete ass-pull, such as Fist of the North Star (you might know who I'm talking about), but most of the time it becomes a plot device when one writes themselves into a corner. Naruto is especially bad with this.