I get where Incubus is coming from pretty well. I was hyped for season 2; ask my fiance, I was doing double fist pumps like I was giving duo-handjobs in a pornotastic threesome when I saw the release date. Episode 2-1 nearly lost me, though (should we call each season blocks? lol Block 2-1).
To be blunt, season 2 was a bigger disappointment than the Peter Jackson Tolkien movies. Yes, I am one of the few people out there who hates the Peter Jackson movies for some of the reasons why Incubus is upset about Castlevania. Do I enjoy them? Yes, but I still hate them. When you play a Lego video game based on the movie and you think, "Oh my God, Lego even knew what was missing," then there's an issue.
Who the hell were all these vampires and why did they work for Dracula? That was as weak of a fluffer plot device as the demon lords (or whatever they were) from TMNT (the 2007 CGI film). I liked that movie, but the backstory and lack of one was horrible writing. TMNT movies could get away with not explaining the turtles' backstories because you know who they are, but why should we care about the ancient lords? Castlevania is a different story. The characters all need backstory. We got that with Trevor, Sypha, Lisa, Alucard, Dracula, Isaac, Hector, and Carmilla - the main cast - but who the hell were the other valpires? No introduction or backstory or any reason to give a shit about them - a waste of breath.
Slogra and Gaibon got tossed in and killed off on compulsary fashion... Even though they're not supposed to show up in the storyline for another 120 years or so! If you are going to do that, why not just throw Sonia or Shanoa in and kill them off as well?
Leaving out various enemies I am ok with and can understand. But DEATH?!?! HE'S IN NEARLY EVERY SINGLE GAME IN THE FRANCHISE FOR A REASON!! He doesn't even fall under Tom Bombadill Syndrome - he's a core part of the lore! Leaving out Death for two seasons would be like if they left Gollum out of Lord Of The Rings until Return Of The King.
As for Trevor's sword, I think maybe they confused curse Of The Moon with Dracula's Curse. I mean, the series is demonstrating extraordinarily well that Ellis and Deats know practically next to nothing about the source FRANCHISE. Forget just being ignorant of CV3 they are ignorant of everything that only a couple staff members (probably the art director) are familiar with. Someone in the art Department probably made the Belmont lair and Deats was like, "What the hell is all this crap in the background?" Then they explained it to him, and he was probably like, "Really? Oh, okay, yeah let's include that. Glad I thought of it."