If people with the level of power we have existed outside of the barrier, they would have been exposed to more battles and war than we are, increasing the likelihood that they die and lose such powers when they are revived.
Your theory is a good one. But I presume that you are not here simply to tell me of your theory. [Not unless there was something he intended him to do with it.]
[Action]
Your theory is a good one. But I presume that you are not here simply to tell me of your theory. [Not unless there was something he intended him to do with it.]