Look in my first sentence, the word "regarded", by this I mean that humanity from our perspective might regard their ability as supernatural(it might appear supernatural on first sight), this is the OP.
In my third sentence I introduced the idea that there might also be supernatural powers, who knows.
An ET for example could be omniscient and omnipotent, from our humble perspective. Everything they could do how ever supernatural it might appear would be through a (omniscient) technology. In this situation the words magic and supernatural become meaningless because everything is possible provided the appropriate technology is being used.