Marcus broke his staring contest with the sky to turn around and see her fighting with the rope. He could see it, it wasn't as much of a metaphor as people thought. He moved down and grabbed the knife from the ground and aimed before throwing it. As it spun in the air it cut the rope that was pulling Avarael back to heaven. It didn't stop her from going back, it just stopped her from being forced back. It was a strong knife, a special one made of demon's blood that was one of the only things able to kill a demon like him and various other species, or cut something like that. After he'd thrown it he turned back to the sky, still trying to figure everything out.