yea i posted about this earlier. Charlotte had some of the worst time-management ive ever seen, with it only being 13 episodes i cant imagine what the staff was thinking having so many of them be episodic "monster of week" oriented episodes while leaving the actual important stuff taking only 1-2 episodes. If this show had 24-26 episodes to work with, it would be excellent and would probably still be relevant in the future, but with that ending.... bleh it just felt exactly as you said. Anticlimactic.
On another note, i did doubt how this would be logistically possible given that he had to go to so many countries and take so many powers, but it seemed like he was gone for like a year or more and he did manage to take like 30 powers a day at least, and i guess it made sense cuz with each power he stole, tracking people down, getting around safer and quicker became more efficient so about half way through his "adventure" im not surprised he managed to actually finish the job.
The last part of the episode was..... predictable.....
i never really like this ship this series to begin with. You could see it a mile away and everyone and their mom wanted it to happen at some point. Part of me wanted it to happen too but it just didn't feel special and the out of character crying and emotion from Nao (even though it was pretty warranted) just felt so romcom visual novely to me.