- The end of Chapter 2 has you traveling through Bevelle Underground to find Vegnagun and destroy it. If you side with their enemy, you'll have to fight the soldiers. Just when you get underground, the alarm blares, signalling their security machinas to destroy you. The haunting music that plays is really unsettling. After you defeat the new leader of Bevelle, you are forced to fight Dark Bahumut. Then Brother cries out to Yuna that something bad is happening in Spira. That's the end of the chapter, by the way.
- Chapter 3 has you fighting dark aeons. While their appearances look evil, so is the boss fight music, complete with scarestrings!
- What's more scary about this game? Oh, right, the bad ending. If you don't defeat the second-to-last final boss, Vegnagun, under the given amount of turns, or if it kills you, Shuyin fires the cannon and completely annihilates Spira.
- The Bonus Dungeon, Via Infinito, has Elder Drakes which can wipe you out without breaking a sweat unless you've been Level Grinding like mad. Normally, this wouldn't be a problem, as there's always the Flee command... except, it doesn't work on fiends you can see before you fight them. You have to time your run perfectly to avoid them, and they keep jumping out at you — and the noises they make as they pounce... *shudder*
- Especially the Tonberries. If you go deeper in Via Infinito, you can even see even bigger ones that can kill you with its huge knife in one hit, even if you're level 99 and have Cat Nip. The Mega Tonberry is absolutely terrifying, with a version of Karma that not only does HP and MP damage, but also petrifies the target and, if that doesn't work, also inflicts 100% guaranteed Confusion. Ouch!
- What happened to Shuyin. Following his death in Bevelle alongside Lenne, the poor bastard spent the next millennium being forced to relive his death and the death of his lover. Over and over, without a break, for a thousand years. Yeah, you can understand why someone might want to reduce the entire planet to ashes after that.
- The Den of Woe is blood-curdlingly terrifying. As if the name didn't clue you in. It's where Shuyin's malevolent spirit resides. It's said that soldiers literally go mad in there, compelled to kill each other, which befalls all of the members of the Crimson Squad save for Paine's team.
- It gets worse, however. If all Crimson Spheres are collected, YRP can venture down into the depths and discover that, despite Shuyin being within Baralai by this point, the pyreflies have recorded his hatred and continue to endlessly cause anyone else who ventures into the depths to experience the same fate as the Crimson Squad. Yuna experiences some protection due to having Lennes dressphere, but Rikku and Paine are driven insane and attack her until calmed. Echoes of Baralai, Gippal, and Nooj are then summoned to attack the girls shortly after they regain themselves. The trio decides to rightly get out of dodge after the battles.
- The music track, "Nightmare in the Den". Shuyin shows Yuna a vision of his last moments with Lenne, which includes Shuyin playing the aforementioned creepy music on the instrument atop Vegnagun's head.
- The bloodcurdling scream Rikku lets out just before Yuna is forced to fight her.
- Also of note are the random encounters there, which introduce an enemy type unique to that area. Not too bad, right? Wrong. Meet the Crimson Shadow, which according to the scan description is an echo of the cries of fear and despair that rang through the Den of Woe as the Crimson Squad candidates met their end. Yikes.
- Players not quite familiar with their Final Fantasy that click on the grayed-out Bestiary entries during Chapter 5 will be greeted by blacked-out models of future enemies. The barren, void-like environment and the moving parts of the models make the massive, camera-shifting enemies look like Lovecraft Lite material. Primal Fear kicks in when you imagine encountering whatever-these-are with color and detail.
- Don't stop the Ronso Rampage in Chapter 3, and in Chapter 4, you get treated to the Ronso going through Macalania woods. Visit it in Chapter 5, and Macalania has a blood red tint in its backgrounds.
Nightmare Fuel / Final Fantasy X-2