Looking at the Tome that disappeared as Wil put away the Book of Destiny; everyone believed that it was indeed a special scroll.
Still, they were skeptical about the time limit as they never heard of such an overpowered skill.
After all, even their Lord Raziel wasn't capable of it. So, they just thought that either Wil was probably got scammed by someone or he was pulling their leg.
That's why, even though they continued to attack the frozen enemy, they weren't reckless about their attacks.
But, as more than 20 seconds passed, they started to believe that whatever Wil said might be true.
After it crossed the 30-second mark, their attacks started to become a bit reckless while keeping their mana in check.