Allow me to join the ending speculations once again. I initially assumed that Yuu will end the conflict by somehow using plunder globally, stealing all powers in one fell swoop
without having to actually travel the entire planet and visit every single power user, which I consider impossible to do within just 2 years. However, it’s not that simple. In ep12, Nao pointed out something that I had completely disregarded: Yuu will have to steal all existing powers and the powers that have yet to awaken. So using plunder globally just once right away won’t solve the problem, because new power users will emerge later.
Time for some simple math. Three years after Ayumi said she was 8 (ep10), the Otosaka siblings were supposed to get captured by the scientists. So Ayumi is at least 11 now, though we’ll have to assume she’s already 12. That’s because about 12 years ago, Charlotte passed by the earth and gave kids superpowers (ep12). Anyone younger than 12 can’t become a power user, since they weren’t around to eat Charlotte’s dust (literally). So we can safely assume that all potential power users will awaken in the near future, in other words, before Yuu loses his power in 2 years at the latest. Let’s say he’ll wait for at least 1 year just to be sure. Within that year, as suggested in ep12, he’ll have to raid foreign power user groups Shunsuke was talking about, acquire a power that allows him to detect other powers (along with the remaining powers of said groups), finally, acquire a means of using plunder globally. One of those groups will probably be in posession of such a means.
There’s alternatives (that may also be just steps in-between), like a power that allows Yuu (no pun intended) to teleport right next to a certain person. That would make visiting every power user within the time limit actually possible.