My bad, I didn't think of that - Soma should be in the Sorrow series. I always felt there could have been one set after DOS, problem being where do they push the story after you've just played through a replica of Castlevania?
There's a novel that was only released in Japan, that took place after
Dawn of Sorrow. The main character of it was Curtis Lang, who was Julius Belmont's apprentice. I
think Julius was passing the whip onto another family since the Belmont lineage kinda ended with him, being too old to have children or something.
But yeah, that was a third entry into the Sorrow series, but it was a Japan-only novel. Which sucked. I wanted to read it, but I can't find any good translations anywhere.
Also, why do people think that the battle of 1999 has to be a full-blown war?
Castlevania III was referred to as a war in
Curse of Darkness, but we saw what that looked like in the end. The battle of 1999 could still be the
Castlevania we know and love and not have to involve armies and such into the gameplay. Only the story. The game itself could still focus around Julius.