Most likely a custom font. While past fonts have been found to some extent, Konami's staff typically made its own fonts.
The B is most definitely customized and is actually quite gorgeous in my opinion.
Looking at the lowercase S, the font is characteristic of cursiva. Such a long descender with that kind of rounded tip is practically unheard of, which reinforces my belief that this is a custom font.
The L distinguishes it as a bastarda/hybrida typeface. The style is not common, but it is far more common than the S - the finalis at the top is supposed to double back across the stem, but it's severed midway, hence the defining bump on the left.
The D is characteristic of bastarda as well. Definitely too rounded to be fraktura or schwabacher.
The double-o ligature may be the defining attribute, but most font identifiers ignore ligatures. Furthermore, a double-o ligature is very rare among typefaces, from what I've seen at least.
The -ed ligature may also be a distinguishing feature. But for the same reason as the double-o lig may be hard to identify, the same may hold true here unfortunately.
One other feature that makes me think this is a custom font is the arm of the T does not cross the stem. Crossing the stem even just slightly is a very, very common feature in blackletter fonts. That this T is missing such a feature is critical. When you combine that with the style of the arm - how it is curved and tapered as opposed to broad like most blackletter fonts - the evidence is almost damning.
What could make things more difficult as well is if some of the lowercase letters are actually uppercase subscripts, which Konami did with the Castlevania III title font. This may be the case with the S. It could even be an upside-down S, since flourished ascenders are more common than descenders.
The closest I've come so far is Duc De Berry font, but that's still a long way off.
Here's what I ended up with trying to silhouette the title font with my crappy Photoshopping skills:

It is entirely possible the font did exist originally and was found in a catalogue of typefaces. Such things have been around for decades and decades.
Their use of a blackletter title font and an antiqua subtitle font leans more toward Nazi German style of writing, I think, whereas using the blackletter font for the subtitle would be more in line with Germanic Biblical writing. Odds are they just liked blackletter more, so they used it for the larger font.
A Franco-Bavarian font style for the title also helps highlight a feminine protagonist, whilst the harsh chiseled subtitle emphasizes her struggle.