The number of monsters on Mount Olympus was increasing, and Walker was completely surrounded. He knew that the flying knife in his hand would be his last resort.
A single strike from it could destroy half of Mount Olympus, even if it didn't harm the innocent. Moreover, Walker wanted to gain rich combat experience.
If he could solve all the monsters with just one throw of the knife, it wouldn't provide much real experience for him.
William knew Walker's temperament. Back during the Doors of Terror incident, Walker had already said he wouldn't use the powerful flying knife. William was curious to see if Walker could stay true to himself.
Walker, having studied witchcraft under Moros and his body toughened by herbal concoctions, was extremely formidable. As long as he controlled the mutated creatures to attack in turns, Walker wouldn't die.
