Finally decided to dedicate some time to completing the After Story section of Clannad.
Nagisa's revival, along with the reset for Ushio also reviving in the anime has always been a little bit muddy, and I've always felt that the ending was a bit of an odd one. I've always wondered whether the anime decided to adapt the bad ending and then "reset" using the lights, or if both scenarios are a part of the true story. Guess I'll finally find out soon enough.