Originally Posted by
VeyaAkemi
My interpretation of why Reaper is because the nature of Darkness in FFXIV lore, which is the inverse of cold=death, Darkness is characterized by Aetheric activity, while ice is an element that by its nature is very still, so perhaps a well-utilized blast of Darkness is all it takes to disperse a lot of ice. "And why not Black Mage with Fire spells"? idk, but if you want an explanation, perhaps fire is simply inefficient at dispersing ice-aspected aether, fire and ice are mutually weak to each other, while Darkness, being a composite "element" of 3 elements, is greater than any given pure element, and so it does the job better.