Lou got a backlash when he killed Osana. He could feel how his energy ran wildly within his body and even though he didn't show it, but he was not in the condition, where he could use his magic freely, let alone to create a massive protection shield for all of them for a long time.
With his current condition, he wouldn't be able to pull it through.
"Lou, they are coming," Ethan said. His eyes fixed at the flock of crows that came toward their direction. "Lou, why didn't you put up the shield yet?"
"I can't."
"You have the magic stones with you, no?" Redmond came over. He pointed at the three magic stones between his fingers. "What do you mean you can't?"
Lou scratched his head and he ordered for the remaining eleven magic users to gather around him. They were not trained magic users. If anything, their skill mostly only average, which wouldn't be enough to put up the protection shield for long.