It Wants To Bring The Sky Down!
The first thing William made was to move half of his monstrous weapons, ten, directly towards the expected directions that monster would hit in the next few minutes.
He had few ideas, but as time was tight, he decided to go with something that could mess the monster's plans; using earth elements to strengthen the area, and also act to cover up what the monster would do.
At the same time, he moved three towards the holes the monster dug. If these holes were important for the monster, then he'd try his best to ruin it.
*Roar!*
"It's targeting my monstrous weapons?" The moment William sent those three out, the monster stopped hitting the holes it was making, and landed over one of them and destroyed it in one hit.
William expected the monster to defend its holes, but the monster moved faster than he thought, and that made him question if the monster was going to do anything initially or this was all a trap.