But Alice's children are also Marisa's, but it's okay for Reimu to kill them? I guess I shouldn't be surprised that reasoning only works one way for Reimu, even people do that, but I thought I'd mention it.
The yukkuris are easily influenced, especially by their parents, the strange thing here is to find a nicehead Alice that rather than letting themselves be attack by the koyukkuris behave more in accordance with his nature