I understand the step away from Demons and Seraphims rightfully so as it seems it has been a focus lately. However, I think under difficult conditions, characters should be able to well, slay some or interact with the demon world and travel to the Abyss after a Long Storyline under rare conditions. With the likes of God and Demon Slayers, I hope we have opportunities to interact with Seraphim and Demons in S3, at least in some way.
I do not know how prevalent Dragons will be come S3. However, if they are prevalent in some way, I hope Seraphim and Demons continue to be also, to some degree. Furthermore but on a somewhat related note, I hope come the changes in S3 that God Slayer and Demon Slayer become unique in their own ways and less generic, with depth not to be outshined by Dragon Slayer but not be put in the spotlight over Dragon Slayer. Anyhow, these are my hopes and suggestions come S3.