Yeah, I don't really want that to be her only reason. What happens when she does think up a reason, hm?

[In all honesty, it's a relief that Castiel's Meg's mysterious friend. It at least means that she probably didn't get the sword from an angel she'd killed or one who'd decided fratricide would be a fun hobby. Besides, he'd quite liked her before the angel connection had come up. He's just protective, really - mostly of his own hide, but hey, Castiel gets a passing thought at least.]

And Lucifer won't hurt anyone unprovoked. Not us, not anyone else. He isn't a threat, not right now.