someone's gonna notice and jump in (money on natsu or gajeel), I don't care how strong laxus is right now (and I'm betting he's ridiculously strong) but 5 raven tail top tier members at once...probably not winnable.
I would agree with Natsu and Gajeel jumping in, maybe Gray too. Sting and the other slayer are also a very faint possibility, (a I'm goign ot defeat Natsu and Gajeel first thing). With their sense of smell it seems hard to believe they would not notice, or else we'll need an explanation at the end.
I'm surprised Mavis had not noticed, or at least shown any real hint of knowing.