Obviously, there were some major complications that came with this particular problem, Tony did get that, though he was having a hard time seeing what the parameters and correlations were. All kinds of people got demon-possessed a couple of years back, and he was pretty sure there wasn't some kind of soul-shortage after that. The real problem was, he was left wondering, "Is that the risk, every time you...?" without the language for it, wiggling his fingers in a mystic kind of way. Because that really didn't seem like a risk worth taking, and Wanda did it a lot. When Tony's hand dropped, it was onto his chest where she had tapped protectively, because the theory seemed too vague to start making claims like that when everyone else's opinion seemed to differ. Even if they didn't even have his sordid past to illustrate that point, maybe it was a soul that let magic people do magic in the first place. Not always in the glowy-hands, energy blasting bad guys way, but all of the little miracles that were foreign territory to Tony, like the way Steve could command a room without loosing a degree of warmth. That, Tony could understand.