User blog comment:Shockmazta31/Why Sibyl Sisters?!?!/@comment-68.98.29.49-20150416094345

You have to remember that the sisters do mutiple elemental types of attacks so they won't deal weak damage even if your element is naturally strong against theirs. This is especially worse for the Light and Dark one since they do 3 types of elemental attacks while the other 4 do 2 kinds.