The titular curse is this, even though it's only subtly shown throughout the game and is mostly described in the opening prologue as causing famine and outbursts of violence. As a result of Dracula's curse, many innocent people lost their lives.
How frightening the curse is can be seen especially in Hector, the playable character. When he is around Julia, he shows how gentle of a man he really is, despite the fact that for the last hour, you've cleaned out a castle of enemies and entered the mountains hacking everything to bits... which leads to the other side of Hector we see the most often: the man on a murderous revenge spree and doing whatever he takes to achieve it. While it can be argued that Hector is only gentle with Julia due to her resemblance to Rosaly, still, the almost bi-polar nature he shows is especially unnerving when it comes to light that he's also being manipulated by Dracula's curse.
The dungeons of the Garibaldi Temple, especially outside Legion's room. And Legion itself.
The basement of the Garibaldi temple. Not only does it have this creepy opera-esque music similar to Ghost Theatre's 2nd floor in Lament of Innocence, but as you descend, the walls start literally coming alive until you reach the bottom and they're breathing and pulsing. Not only that, but there are floating bubbles containing concentrated evil in the form of fetuses (called "Evil Cores") that try to suck you into them. At the very end of the hall, there is a door which leads to the Legion bossfight, which is the same idea as the aforementioned Legion boss fight in Symphony — a giant ball of corpses. Only here, the entire room is made of corpses.
The corpses themselves are this. They raise from the ground and walk quickly toward you in a freaky and wobbly way while there heads jerk side to side, instead of attacking directly, their heads explode on you, causing massive damage...
Similar to the Undead Parasites area in Lament of Innocence, the whole scenario to the basement of Garibaldi having "living" walls to the room where you actually fight Legion and Nuculais. It is never explained what the hell is going on. In fact, this is yet, another disturbing hidden area many people would likely miss like the Forgotten One in "Lament of Innocence" and maybe for the best.
The boss music for Legion is also scary, reaching its peak as the massive abomination is slowly revealed. Thankfully, the following boss, Nuculais, may be eerie, but is far less scary. Actually, when you see him opening his mouth, he'll fall into the Nightmare Retardant category!
The Ectoplasm enemies are faces molded into a purple, spherical blob. As they get near you, attack you, or if you kill any of them, you can hear sounds of wailing women. But fortunately, the Background Music drowns these and can only be heard clearly if you are in close proximity to one.
Sitting in the Park Swing when it's unlocked in the Chair Room. The sky suddenly turns orange, the Background Music becomes muted and gets replaced with the sound of wind and crows, and the description doesn't describe what Hector's sitting in, but instead describes the thoughts of a lonely child whose friends have gone home and awaits his mother to return. It can be surprisingly eerie and a hell of a Mood Whiplash compared to the zaniness of the other chairs in the room.
Heck, the Chair Room itself might as well count. The music and how out of place everything is, along with the bats flying around that can be shot down for no real purpose, can give off a really uncomfortable vibe the longer you stay in it.
similar to Ghost Theatre's 2nd floor in Lament of Innocence, but as you descend, the walls start literally coming alive until you reach the bottom and they're breathing and pulsing. Not only that, but there are floating bubbles containing concentrated evil in the form of fetuses (called "Evil Cores") that try to suck you into them. At the very end of the hall, there is a door which leads to the Legion bossfight, which is the same idea as the aforementioned Legion boss fight in Symphony — a giant ball of corpses. Only here, the entire room is made of corpses.