"What kind of curse?" Shura can multitask, winding the rope and tying knots as best as she can. Taking care of the curse might solve the problem of who was controlling it, but that didn't take care of the the wolf itself. Shura had been willing to capture werewolves, but only because they'd change into a more manageable form after a while. This guy might be happy to chomp on a few more civilians once he was free.

"I can try somethin', but one of you has to cover me. I can't do it and defend myself at the same time." And by one of you, Shura means Billie. Whatever Daud was doing, he's in no shape to protect himself, let alone do anything else.