I understand about Alpinia, Kerria, Anemone, and Cherry. The first two is boss killer with drain property. Anemone, while has lowest TP among rainbow, has potential to 5.4x damage on one target. And Cherry can lower attack, which I heared it's very useful against late game pests.
But why Ionocidium in the list? She has almost identical skill and passive except one can dodge, and the other can nuke?