[quote=Kafka Komedy]
No idea, but based on estimations of where exactly Brace and Mag are in the club compared to where the alley is, I think they'd hear him making a ruckus.
[/quote]

I dunno, it's a club with loud music....

And sadly, angels and demons cannot sense eachother. Demons tend to stick out, though, while Angels have the luxury of blending in as a human. Besides the weaponry and the superhuman strength and the ability to go to and from Heaven and Hella respectively, they're normal people with normal senses.