I think you get hints that they're alive and doing stuff, but Isamu's and Chiaki's transformations seem to come from out of nowhere, though you do get the sense that them traveling around in the Vortex World is warping them since that place is not kind to humans. Seeing their shifts in ideology has been great since I went into this game thinking it was just a simple dungeon crawler but it has a pretty good story in there.Yeah, shes definitely the most "happy" ending... sort of. Some of the IV characters do change near the end, but nothing as drastic as in Nocturne. They drop hints all throughout the game how they're going to turn out, while Nocturne's are more drastic. There's hints about Chiaki and Isamu, but still pretty subtle.