"Even if I ended up away from the place of this battle, it won't make a difference," he already told Sloth to activate the formation the moment they finished it. And like that, the dark leaders would get another problem to solve, a disaster they couldn't handle.
By this time, they'd feel like they got their house made out of glass, and they had to stop the approaching falling burning meteorite shower from the sky.
William kept digging and didn't care about anything else. He estimated to keep doing this for two hours before he'd start heading towards the surface again.
His digging speed wasn't slow, but the reach of the fire sea he started was enough to cover up kilometres around the gates. So he had to make sure to not make a little mistake in his calculations, ending up in the middle of the deadly ocean of fire up there.
