With the fierce power added from these big war machines, it'd be quite hard to stand against their attacks.
The deadly force sent by the ballista was important, but far more important was the grade of the arrows used. If they were made by high-end artisans, then they'd be very lethal.
The moment William spotted these ballistae, he knew this was going to be harder than he initially thought. Evading these arrows wasn't a problem for him as long as he was on the ground. He kept dashing right and left, stacking attacks on his tails, while taking note of the incoming arrows.
The arrows flew fast like they were lightning bolts. As he moved fast, in an unpredictable course, the arrows all missed him. The moment they landed on the ground, they left deep holes there, with loud bangs with every hit.