Hmm, playing this over such a long period with many breaks, my memory is a bit fuzzy.
On my current save, Emma's status is girlfriend. Not sure exactly what I did to get there. I remember modifying her body to be not fat anymore.
My main question here is what are the different paths for Emma? Was there an option to use the serum on her before? I would rather have MC corrupting everyone than having some heartfelt romance with Emma hehe.
The situation with MC + Emma romance + corrupted Vera is a bit weird. MC and Emma talking like Vera is a big problem and they need to be careful of her finding out, but isn't Vera pretty much a slave at this point? I mean she has some agency and a bit of her personality, but she can't go against MC.