A game in which he would become Dracula or finally get off the dark power of him.
Soma will never find a way to rid himself of the Dark powers because it was he whom created those powers to begin with. Soma's soul is that of Dracula. Dracula was reborn as Soma Cruz. Trying to segregate a part of yourself is impossible due to the nature of the soul so Soma, like it or not, is stuck with that power. But like Yoko said in AoS, it's more like a weapon. The user decides if its purpose is for good or evil.
I think I wouldn't mind another game with Soma in it. The only thing that I would like to see in it would be a much better and more solid story then what we got in DoS. Also the game could use a better title then constantly reusing the 'sorrow' part. An no more using souls to make weapons. That slowed the game down way too painfully for me. I'd rather just find them or buy them.
-X
Agreed. I believe someone is translating a CV novel in the "fan stuff" area of this forum. While I don't know much about it, it could be cool if it was made into a game.
Aside from Alucard, Soma is my favorite CV character on the side of good. I just don't like the fact that he becomes absolutely defenseless once he is out of danger. He needs to find a way to retain some of the abilities he absorbs so that he can protect himself and Mina. I mean Arikado/Alucard, Yoko, and Julius can't be around to protect them 24/7. I would also like to see Death with a larger role other than just being another boss. I mean if he is as high up on the food chain as we are told, he should at least realize that there is something about Soma. I mean from what I've heard, in the novel, Death approaches Soma and he knows who he is.
I think it'd be more interesting to see what happens to Dracula's soul AFTER Soma dies. Would he be reincarnated again? What if Soma eventually has children, what of their fate? 
This would be interesting too.