Currently thinking about how there’s no way Lucina wouldn’t have gotten at least a little re-traumatized by the events of World of Light.
Here she is, thinking she’s gonna get to spend some quality friendly sparring time with dear old dad (and Robin) again, and like a day later or whatever, this light monster shows up and obliterates the world in minutes, and there’s nothing she can do to keep her loved ones safe this time.
Next thing she knows, she’s waking up in a dark, alien, hell dimension that probably evokes memories of the bad future. If she’s lucky i.e. when I’m playing lol, Chrom and/or Robin will have already been rescued by the time she’s found. But neither of them are mandatory recruits, and in fact Chrom is relatively easy to miss entirely, so there’s some fun food for your thoughts.
She’s already prone to nightmares in Awakening, no way in hell would they not come back with a vengeance after this shit.