- How does Miriam gain new powers? By killing her foes and absorbing abilities as shards shards that jam straight through her torso, which she has to forcibly aid with visible stress in the process. And as of the E3 2018 Demo, she screams in pain when she absorbs one. Apparently it's even more uncomfortable than it looks, with Miriam describing shard absorption as claws scraping against her bones.
- Valac, the double-headed demon serpent boss from Curse of the Moon's stage 4, makes a return. Those who didn't know, or those who weren't paying attention to his design in Curse, might get jolted by the bloody corpse under his chin, and that's before he properly greets you with his many, many teeth and centipede-like bodies, along with a rather claustrophobic boss arena.
- The lengths the Alchemist's Guild went to in the name of sheer, naked greed. They infected children with a blight that crystallized their bodies, then ritualistically sacrificed them to summon demons, resulting in a Hell on Earth that is plainly stated to have killed millions. All because scientific progress and the Industrial Revolution were drawing away their wealthy patrons. There's no suggestion that The Extremist Was Right, either; this was entirely done out of pure avarice and fear of change.
- Arguably making things worse is the classic ultimate goal of alchemy—the Philosopher's Stone needed to create the Elixir of Life, which would grant total immortality. Never mind just avarice—they were arguably so determined to cheat death outright that they were willing to risk killing everything else off.
- The Easter Egg found in the runaway train. There's a chair within the train that players can take a seat in during subsequent visits, which triggers a scene reminiscent to Alucard peering into the telescope of the Outer Wall in Symphony of the Night as Miriam looks out the window of the train. However, if you have her sit still long enough, players will witness Miriam's vision dozing off during the ride, only for a strange entity to appear in the distance. If the player lets the scene play out, the entity steadily gets closer and closer, only to suddenly vanish from the scene and WHAM! The monster suddenly jumps right into the player's face and screams at them, and if the player didn't have Miriam run away from the chair as they would from their console/PC in real life, they are treated to a fight with the Kunekune, a Boss in Mook Clothing that can also inflict Curse on Miriam, causing her HP and MP to be cut in half, and the Kunekune is a very strong enemy that will likely send unsuspecting players to a Game Over screen, being able to deal damage and Curse Miriam just by having her be facing towards it. To make matters worse for completionists, they'd have to trigger this fight many times over if they plan to get the shard it possesses and upgrade it. Have fun.
- Den Of Behemoths, which is the beginning of the endgame. At first you think, great, we've ratted out Gremory and found the way to the final dungeon! And then you arrive at Den of Behemoths only to be greeted with glaring crimson background, and as you go further, you then learn why the place is called Den of Behemoths: The enemies have been significantly upsized, and even your formerly frail mocos and mortes become gigantic with tons of health. Imagine being in Miriam's shoes; she has gotten used to foot-sized frogs, Morte Cannons about her size and suddenly she sees these demons dwarfing her (especially that giant moco which bursts out of a giant boulder she is merely climbing). The oppressive music doesn't help matters.
- Dominique's true nature. After having spent her entire life devoted to God, only to watch Him remain utterly silent as mankind suffered and died to the Demons, she decided that if God refuses to do anything, she will usurp Him and take His place. This new mindset led her to become obsessed with amassing as much power as possible, driving her to form a pact with Gremory and instigating the entire plot, being willing to unleash Bael upon the world all for the sake of obtaining ever greater power.
- Here's one laden with Fridge Horror. When fighting against Bael, you can attack any of its heads as you wish, but doing so will only put that head out of commission for a short time before it's back up again. In order to do any real damage onto him, you need to attack the head that Dominique is perched atop of in order to truly defeat it and send it back to hell. Which begs the question: what if Dominique wasn't there? Would this not make Bael literally unstoppable, without a literal weak point and controller? If humanity was screwed over for ten years by the demon invasion, then it would've been completely turned to Hell on Earth if the Alchemist's Guild managed to summon Bael!
- The Unnamed Alchemist's journals. They detail the original creator of the Crystal Curse's attempts to summon demons to the world, in hopes of keeping the Alchemist's Guild afloat and their coffers flowing. It details how he went about with his crystal project, how he found out that using children would hasten the curse's progression. After being given children to experiment on by the Guild, he then forces them to bind shards, of which Miriam had said "it felt like claws scraping against her bones". At the end of it all, he expects them all to be sacrificed to summon demons en masse to the world. How does this fit into Nightmare Fuel? Simple: the entire journal volumes are like reading from the perspective of a mad scientist who doesn't care how many people he has to kill and hurt so long as he and the guild profits, up to and including children. He has absolutely no remorse for his actions, and only seems to feel regret when Gebel is back to finish off the Alchemist's Guild (which is likely less My God, What Have I Done? and more Oh, Crap!). Perhaps the worst part is that it can paint some unsettling real life connotations on how some institutions make use of child labour without caring about them, and only using them as a means to an end.
Nightmare Fuel / Bloodstained: Ritual of the Night
It's not surprising that a Spiritual Successor to the Castlevania series would have plenty of Nightmare Fuel of its own.