"You already have the connection, don't you? You were born with magic, whether or not you knew it," Dorian said, his fingertips drumming on the ancient, dusty cover of one of the books he'd started reading. Of course he would not find the answers to everything in that library, but he was convinced it was very deliberately stocked - already he had seen similar, familiar writings on Necromancy like those found in Thedas, tomes that he, himself, had cracked open once upon a time. "Whether or not magic is pulled from the Fade, as with those of us from Thedas, or whether it's pulled from the air around you or some otherworldly pool, it's that connection you have which allows you to do that."
Emotion was a universal construct, and the Fade itself - where mages pulled their power from - was shaped by both emotion and will; provided that they had the 'mechanisms' in place, a predisposition for learning magic, Dorian was convinced anyone could.
"A guardian is a good way to put it. We are tapping into the Fade, for our magic, if that construct was explained to you - and spirits reside in the Fade. But the way we learn Necromancy is by calling upon these spirits to teach us, even - I am certain if you ever wanted to call upon them, your connection with magic would let you." He'd help, naturally. That went without saying.