[quote=ImportantNobody]
No more flames would be going out to conceal the wall, but I'd imagine him charging forward would be done within...what, a second or two? I would think by the time the flames dissipated he'd already be well on the way to reaching the wall.
[/quote]

According to Drall's post, he threw up the wall as soon as the flames obscured the entrance, which would have been right before the retaliatory gust of wind. Arthur can't actually move when he's using the gusts, so his gust would hit the wall before he started moving.