If you have any Spectral Revenants, you should put them in - cut the Shadow Nova and Void Pulse. If you have them, 1-of Klaxxon and Variax can provide sticking power for longer games.
Personally, I'd run it with Cassy, Nocturne notwithstanding. Without Soul Grimoire, Shadow Dancer, Shadow Watcher or Death Fire Crescendo, there's little point in building a swarm.
Of course then what you'd be left with is a bog standard meta viable creep deck