After a few hours, he noticed that the grenades thrown out by the two monstrous weapons weren't creating any safer spots. So, he started to rain down the ground with his explosive arrows and grenades every time he got time to.
He made sure to create a few landing spots, as he wasn't sure of where he'd land under the fierce pursuit of the flying monsters. Yet what he did greatly decreased the pressure over his two monstrous weapons, letting them fight more freely and kill more monsters than before.
William was feeling the pressure since the moment he started doing this. He was fighting a hectic battle in the air, while controlling his two monstrous weapons to kill monsters on the ground. Not to mention he had to timely detonate the grenades, to not let any of them be missed, or he'd move away from their detection range.
Jumping to the air, fighting flying Hornets, ending up landing on the ground at a safe zone, William kept doing this for long hours, even days!