Let me review the updated version.
BTW, you requested me to review this in my "Kep Reviews your Level" thread, so I shall therefore fulfill your request.
Design - 9
The design for this was downright astonishing, and the whole time I was playing this I felt like I was in a fantasy. To immediately start giving criticism, though, I disliked how this level really had no main gimmick. I mean come on, this is Castlevania. You could do anything with such a great and difficult game like that. Also, the music for the boss didn't necessarily fit since it sounded more ambient and calm than intense - but oh hell, that boss is another thing. Let me just put it this way: It was unfairly difficult, and the unnecessarily placed fire replacing Rinkas just made it way more complicated than it should have been. Not to mention, he took FOREVER to beat, I mean, probably around thirty hits if you wanted to get technical. Make him replace someone like Motherbrain and with events make him move around or something, but just don't make him replacing SMB3 Bowser, since it turns into a disaster. Anyways, the gameplay. It was excellent. When I was playing this, as said earlier, I felt like I was in a fantasy, and I was just beaming at how visually appealing this level is. All in all, you definitely deserve a nine for this category.
Atmosphere - 10
Truth is, I've never given anything a ten ever on anything, and I've been reviewing levels since SMBX: Revived was around. I mean, the atmosphere and aesthetics were downright perfect. The darkness was perfect, and the background objects placement was just right. I have no complaints here; great job!
Placement - 8.5
The placement in this level is barely lower than a nine, for a couple reasons. Firstly, why have Goombas coming right at you right when you start the level? This is a problem with almost all SMBX levels these days. Give the player some time to breathe before starting, please. Also, no points will be taken off for this so don't worry, but why not have some ceiling in the outside section? It wouldn't hurt, but that's more of a recommendation than a bug. In addition, I don't think the dragon coins fit that well. If this is Castlevania-styled, why have a picture of a Dry Bones on it? Try to add a custom and cooler picture for the Dragon Coins. By the way, what's up with the weirdly animated Boo things replacing the Eerie? It kind of looks like it's shaking its ass or something, I don't know. Try animating something else on it, like its mouth or eyes. Conclusively, at one point in the outside section, there is a part with four Dry Bones lined up and this could be classified as cluster.
Your overall averaged score is...
9.16
Ironically enough, me and Natsu's score were very close. Nonetheless, I'll send this to the level judges to try to get this approved, and if it does, you'll go from Pretty Good to The Best!