The magic was coming from your hands, [ Strange adds in, as if this reply makes perfect sense. Which is interesting. Unlike Strange's English magic which mostly serves as the go-between from Strange to elements, this magical power was coming directly from Yuya himself. ]

It obviously doesn't have to be physical touch, but perhaps it's based on proximity as well as sight of what you're targeting. What if you try to ward a building that you can see, but you're further away from?