"It is. And... right. I keep forgetting that there are people I haven't told yet. Aether is the substance that makes up everything in my world, from memories and souls to the ground you walk upon. It's generally aligned with an element, and the practice of intentionally moving, channeling, and shaping aether is what we call magick. It comes in many forms - though the balance between the elements is extremely important. Enough shifts and draining of certain types of aether can cause a Calamity. It's... as it sounds, and it's happened seven times in my world."

He even remembers the causes of all of them! Though the Sixth was a particular area of study given its connection with mages and his time in the Thaumaturge's Guild.