[Minako doesn't blame Aigis for any of it. What could have happened then, without anyone to stop it, was even worse. At least her gambit had given them time, enough time that she could grow up and actually fight back...]

Right. Her memory was damaged but she still sensed I was the same person.

Anyway, all that time with me... or with Minato, I guess, made Ryoji-kun more human. That's why he took a human form and even made himself forget he was a Shadow for a while.

[She sort of idly wonders if Ryoji had acted the same way after living inside a person like Minato. Had Ryoji absorbed her traits, or was his personality all his own? Maybe someday, she'd ask.]

He did all that because he'd remembered his real purpose when his pieces came back together. "Death" serves another being called Nyx. Nyx is... something like a goddess. Shadows are like pieces of her, and she brought death to humanity a long time ago. Ryoji-kun's existence then meant that Nyx was going to come back and cause the Fall Ikutsuki had talked about before.

Basically... when Nyx arrived, everyone on Earth would become part of the Lost and the world would end.