Luxen found the young Slytherin's comment annoying. She obviously thought she was being clever. "Oh no! Someone thinks she's a Ravenclaw, well here's a concept your bird brain might understand. Guilty by association, your dorm was loud enough to wake the real Ravenclaw's up in their towers" Luxen said snidely as he began to walk forwards.
He wasn't interested in picking a fight with a couple of first years that were unable to defend themselves magically. At best and without lessons the most they literally could do was the simple Lumos spell. He on the other hand had a whole arsenal of tricks at his disposal. The fight was simply too one sided for his taste. "Little firstie, if you're as smart as you think you are you'll take my advice and tell your mates to shut up at night before someone less 'friendly' decides to actually teach you a lesson" Luxen said as he simply walked past.
"By the way, tell whoever was singing, she sounds like a merperson above water and needs a good muzzle" he added with a smirk as he walked on.