"But what about Marion, then?"
The valid question was left unanswered for a while. Chiaki found her brain cells ran on a treadmill squeezing answers out of it, but she couldn't. Until she realised she had used a different starting point, because she saw no connection between Marion and Natsuiro.
She tried another way. Marion was part of System. She was part of this universe, and that meant she wanted the universe to survive. It was only logical, alright? This realm wanted to preserve itself. That was human nature. That was a natural instinct, because every organism had self-preservation. The survival mode was even stronger with this realm that had been designed to achieve the social singularity by Frost Flower and Chihiro.
Okay, that was clear, then. Marion wanted this universe to stay, so she must ensure all parts of this universe were stabilised against the attack from Natsuiro.