Considering that there will be probably a way to reverse the transformation,as i dont think Dorry and Brogy will remain demons,do you think it would be a cool idea to also see some Strawhats in demonic form during this arc? And if the answer is yes,who? Imagine Usopp in a demon form,maybe he would be freed from his fear,but at the same time,at some point during the story,maybe when he is about to do something particulary evil,he could manage to free himself from this "curse" alone,making finally something cool in Elbaph. Or maybe Nami,from the women i choose her,because Robin has her own transformation that its similar to a demonic one,so it would not be a very much new thing if she was the one trasformed in demon. Or maybe one between Zoro and Sanji.
they will die and be permanent demon under Mu