In a story idea I have, there is a race of humanoid creatures that evolved on earth from organisms that originated from another part of the universe and possibly another dimension. Their brains are unnaturally advanced and they seek to learn all that can be through experiments, sometimes at the expense of innocent people.
My idea was to include my own concept of arcane. In the story, the race's definition of arcane is something that seems impossible to those without the knowledge of how to do it. For example, conjuring a ball of energy would be preformed by, say, thinking of a certain alien image while twitching fourteen specific muscles in a quick sequence, or something like that.
That way I could get away with saying that magic is just things that normal people are mentally incapable of thinking of, as it would break their understanding of reality and induce insanity.