[It'll take a while, but he gets hit with the event, too. Everything from before he voiced out his choice to 'protect the world where Fuuma and Kotori could live' was erased, and is scattered around in the shape of shards of glass.
The more violent things are more difficult to see, but his memories of Fuuma and Kotori aren't - they're the ones he treasures most, afterall, the things he doesn't want to let go of even if they hurt to remember]
[He'll be wandering around the main island, in any case, worried about the state of things and confused about the scars on his hands, unable to recall how he ever got those]