Here's a LONG list after a small talk with some of my friends
Iron blue intention
Carrie's ending theme (CV64)
Belmont's Theme (Lords of Shadow)
Red Dawn (Stage 5' in Dracula X Chronicles)
Annette dialogue theme in Dracula X Chronicles
O.p.13 (Rondo Stage 5', in some soundtracks it was misplaced with Slash)
Abandoned Castle (Curse of Darkness)
Followers of Darkness -The Second-/-The Third- (Curse of Darkness)
Belmont the Legend (Curse of Darkness)
Dracula's Castle (Curse of Darkness)
Prologue (SotN)
Stillness (SotN, unused track?)
Etude For the Killer (Castlevania Chronicles PS1)
Awake
proof of blood
Repose of Souls
circle of the moon (Circle of The Moon)
Chapel of Dissonance (Harmony of Dissonance)
An Empty tome, Wandering the Crystal Blue, Sorrow's Distortion, Lament to the Master (Order of Ecclessia)
Riddle
I'm not sure it would fit this type of situation. It seems like it belongs in a church or cemetery type of setting.
Stairway to the Clouds was originally used as the theme for the long bridge before the Castle Keep Throne room in CV64. The Combo with Illusion Dance gave the whole Castle Keep music doubled awesomeness.