I don't think the perfume would be very effective against them. Since the perfume is made from Eric's pheromones. Eric while able to see glimpses wouldn't be effected. As for Shell, the pheromones were produced when Eric was aroused and Shell is quite use to that. So he might just get horny from it. The bigger problem is the insane human and the serial killer art dealer vampire.
both are good vampires, but Humpty doesn't know or see that. Humpty might go after Pain Overlord next for taking away Ellie. Humpty is a rather conflicted person. He did go to kill the one he loved since he believe he was left by him not realizing that he left to protect the family he has and even invited humpty.
I believe it can be handle by consuming Eric's blood. When Eric's pheromones was used Humpty Dumpty and this other guy was not effected (I guess it's only the vampires? I don't know if its the same for humans). It was mention he drank some of the hybrids blood which I assumed to be Eric's blood. Meaning Erics blood can withstand his own pheromones. And Shell already covered cause has drank blood from Eric and maybe already used to his pheromones.
How can both of u fight with that situation dears, Shell and Eric?