Anyway, if that doesn't suit your plots, you don't have to link the blue gloves thing to the genetic engineering. But you can keep that last part anyway, because it would be a good way to explain why they aren't affected by their killing device.

And.... Do you really need to explain the aim of the blue gloves?
Considering that there'll finally be a Firelfy movie (yeah!!!!), what if they explain them in it and that it's totally different from your explanation?