Mana was a sensation unbeknownst to anyone on Earth. It wasn't a type of energy that anyone there knew how to channel or use. However, that wasn't the case anymore. Ever since Luke found himself capable of tapping into an unknown source of power, Nate too was left curious as to what he could do.
Their primary reasoning behind why and how Luke could see through the dark, in reality, was because of the curse. There were only two beings cursed by Primordials, and coincidentally that was Nate and Luke. To say that their display of magical abilities was connected to this would not be a stretch.