Before Leon could find a place to hide the angel's body, he felt Sylas was about to appear. In the end, he just teleported her away to Miebos. That probably wouldn't change anything since it was only obvious that Sylas reached a level where he could feel the presence of all his allies, but then again, Leon didn't want to let him try to undo his spells on her.
While Leon was passing the message to do the same thing to all dragons to his replica, Sylas appeared. As expected, he was mad. His glare was powerful enough to make Leon feel shivers.
"Where is she?" Sylas asked.
"In a place, you will never find out," Leon replied.