The Replaced are likely to start interfering more with Yayoi's plan, and in that case, all she has to do is kidnap and make them a kodoku jar out of their group.
Keitarou is disturbed by her saying that, but realizes she might just see it as retributive justice. They need to strengthen their forces, no amount of preparation is enough as they've learned. Eiko suggests getting a car too, when Ai gets a phone call.