In my mind, I kind of pictured adapting the original Castlevania kind of like Genndy Tartakovsky's Primal. Just Simon going absolute beast mode on Dracula's Castle. Just do it as one single movie of awesomely animated, musically energetic madness.
Simon's Quest is where you get to go a little deeper into his humanity, even as the curse is taking it from him. He's forced to open up more to people.
I really wanted to see Simon's barbarian design adapted to the show, but oh well. It's fun to dream.