So...remember this?
I just realized that as a hemisphere, the height of a dome is equal to its radius, not its diameter, so in order for Luzurial’s head not to be brushing the roof of the dome, the radius of the thing has to be something like 2 meters (about 6 feet 7 inches), which means the diameter is 4 meters (a hair over 13 feet) at the ground level.
I apologize for the math-based stupidity from earlier. I’ve gotten better at it over the years, but sometimes basic aspects of geometry still escape me.
In case you’re curious, if I’m doing this right, it would mean that assuming Luzurial is 6 feet (1.829 m) tall, then the wings sprout from her shoulders, which according to what I could find online are about 82.1% of the way up your body (1.501 m in her case). At a height of 1.501 m, the diameter of the barrier should be 8 feet 8 inches (2.642 m), so with that 15 foot wingspan, she’d be able to spread them more than halfway, which should allow her to beat them somewhat, though obviously not at full strength, but would also allow her to press them against the walls of the dome.
Assuming I didn’t just screw up the math again, that is.