It's useless, you know? Futile. Waste of time.

She has created those puppets. No one in Gensoukyou can stop her anymore.

She will continue to make those puppets until her power is exhausted.

In her mind, the girl no longer thinks there is only one kind and gentle Marisa, and has accepted that as her "Reality".

And also, Marisa too, will continue to kill the puppets until her power is exhausted.

For the sake of her own beliefs and responsibilities. She is entirely willing to do anything, even if it means losing half of herself, and even her companion.