i think it's her brain
if that were the case, I don’t think she would’ve been smiling when she talked about it. it’s kind of light to ask for her brain when the other reward for the ratri dude was for his whole lineage to carry the burden of onlooking stuff between the human and demon world
I think maybe it has something to do with her lineage(if not her). Like she has to have at least more than one child and allow the Demon(Deity?) to have one she raised to be brilliant.Like a family sacrifice for demon-kind or like being a mother but not under a system.
I think the reward for the wish might be Emma Staying behind along with Ray and Norman. If not that then it’s her brain or someone else’s brain that is close to Emma.