Per wiki policy, Spoilers Off applies here and all spoilers are unmarked. You Have Been Warned.
- The game has its share of bad things, but Nefasturris/Nefascapitis are among the freakiest. First of all, it comes to life out of a skyscraper and is a gargantuan demon composed of a whole mass of small bat-like vermin and stares at you with a clear, exposed eyeball. When you defeat it the first time, you have to fight its head, named Nefascapitis... Which stands on its own with its lower jaw split open. The design alone for this monstrosity is chilling, what with its body that looks like a Greco-Roman statue going into decomposition with exposed flesh, a horrific wide mouth with a nucleus inside that fires lasers of several types, and its creepy rotted eyes staring at you. As Nefascapitis, its teeth also wriggle nonstop.
- Arius's building near the endgame, where both Dante and Lucia must ascend to the top floor. As you proceed, you find key items that twist the area even further, the walls covered in membranes and the hallways twisting and turning... And then that demon named Trismagia shows up. His regular appearance is that of a gigantic, three-faced head with four eyes. As the fight begins, he splits into three individual faces. But if you look closely, you'll notice that he can't separate his body as easily as he fuses. He instead painfully writhes around for a few seconds before forcibly ripping himself apart, with blood splashing into the air. Seeing as Trismagia tends to return to his base form periodically to fire a single, powerful blast at you, you'll be treated to this wonderful visual multiple times. Each of the faces has its own elemental affinity and associated emotion (anger = fire, melancholy = ice, and joy = lightning). Unsurprisingly, the lightning face with its Cheshire Cat Grin is the creepiest-looking of the trio, and is even worse when it comes close to the screen. Its voice is also rather creepy, like the sound of someone who's had their throat slit.Trismagia: The Son of Sparda... You must repent your sins!
- In the final level, the influence of the Demon World has spilled out and warped Dumary Island into something horrifying. The town is now covered in webs and weird-looking cocoons, the waterways are blocked by the same webbing and even the buildings themselves look odd and twisted, some of them at weird angles. The creepy music doesn't help.
- The boss for the level? Phantom. Somehow, Mundus' servant came back to life to fight the player once more. His presence does, at least, sort of explain the town's new look. After all, it's covered in spider webs and cocoons.
- Argosax the Chaos. A wide, malformed, shapeless conglomeration of several previous bosses from the game. It's disturbing to watch each individual part of these beasts in that mass of fleshy goo writhe and twitch as if they're in constant, never-ending agony, nothing left to do but once again try to kill Dante with their repeated attacks.
- We only know that Argosax became king of the Demon World centuries ago and that Sparda once defeated it. There's no in-game explanation as to why its first form looks like someone took the previous bosses and just mashed them together into a disgusting heap of flesh that writhes, with even Griffon being a part of it. Either Argosax already looked like this (which raises a lot of disturbing questions), the previous bosses were extensions of it, or it assimilated the bosses into itself. The latter theory is backed up by the fact that Argosax's first form is only a shell hiding the real boss.
- While not nearly as frightening as its "shell", Argosax's real form, "The Despair Embodied", still has some uncanny characteristics to it. The fact that it looks so angelic and bright despite being a demonic entity, being so fast and near-unflinching, and the fact that its vocalizations sound like Dante and Lucia's voices, pitched down.
- First-time players may be in for a Jump Scare or two, as the fight starts with Dante and The Despair Embodied on opposite sides of the battlefield. Your first instinct would probably be to slowly approach it from afar while firing your guns (since that works on pretty much every other boss in the game), only for it to suddenly teleport behind you in the blink of an eye and start wailing on you with melee attacks. The fear factor eventually goes away, if only because the boss is so unrelenting that you will be constantly dodging throughout the battle and eventually acclimate to its behavior.
- Lucia's final boss, Possessed Arius; what was once a greedy, megalomaniacal human sorcerer is now an aberration with creepy tentacles sticking out of his back, constantly charging towards the player like a wild beast without control. As it turns out, Argosax's power reached through the portal and corrupted Arius to make him kill Lucia, which adds more to Argosax' power and nightmare factor: this monster is so strong, it can transmit its own essence into the human world through an open gateway without ever leaving its spot in the Demon World.
- And just because Arius wasn't enough of a monster, his first defeat in his demon form results in even further corruption, turning him into Arius-Argosax. Whatever human traits Arius still had are now completely gone, replaced by a gaping mouth with teeth made out of ribcages that spews out poison like a waterfall, a huge black body with scales, claws and a thick tail with glowing spikes at the end. The mere way this thing moves is creepy, even within the confined space of the crevice you fight it in. The only thing that possibly mitigates the scare factor is the fact that the boss is disgustingly easy.
