View character profile for: Shadow Walker
View character profile for: Black Emerald (NPC)
OOC: How did Black Emerald come to find Cassia at that exact moment? She entered the city under a spell of disguise. So writing about how Black Emerald saw through this gives you a perfect opportunity to flesh out your character.
If Black Emerald is a soul or ghost how does he exert control over his minions?
Can he take physical form? It will get quite tricky with the Shadow Walker as the physical body, Black Emerald as the soul and who then is the mind or will of the shadow walker? He's still making decisions, just not guided by a conscience.
As it stands now Cassia would most definitely not want the Shadow Walker to be reunited with it's soul. She'd actually want to use it's soul for her own purposes. That of course is player knowledge so Black Emerald would only be aware of what she tells him. So have you a plan to entice her towards your agenda?
These are the questions that I'd personally like to see you address in detail over your next series of posts. Its all optional, but would help me to understand your character which in its current iteration seems undefined.
Otherwise I don't see how the relationship between Shadow Walker and Black Emerald can stand as you've tried writing it and we'd need to edit their character sheets to eliminate the connection between them.