Gabe rested his hand against the edge of the desk, watching William practically sit on his, getting them out of reach. Right. That answered that question, and it wasn't like there'd been any call in the first place for the tiny little hope that had just shrivelled up inside him.
He couldn't even really be distracted by ridiculous suggestions. "Fiendfyre?" he repeated, eyebrows up. Just how rattled was William to even think it? "Not unless there was no other way. And probably better keeping the skin as whole as possible. It's the body's natural defensive layer in any case, against magic as well." He drummed his fingers, thinking through options. "Muggle tattooing might actually be the best course. Keep the process simple, strengthen the natural barrier..." He shrugged. "Theoretically, it's possible. I'm just not sure you can make the warding general or strong enough. If all you can keep out is mild bad shit or a specific range of curses, is it worth the trouble?"