Doubly so if you're playing Maya. Whatever it is they're seeing? When you Phaselock them, they see it more.
A bit of Fridge Horror: Siren powers are all based on phasing things into another dimension. They're seeing into another dimension... The same one that Sirens can access, which may be where The Destroyer is from.
Knock off a Goliath's helmet and enjoy the resulting Body Horror: the flesh around their head flakes off, their skull bursts from their mouth suspended on their elongated spine. That's when it starts to chase you everywhere.
Just to show how terrifying they are to fight, they not only turn on whoever they were helping if you're not around, they get stronger for doing it. Every time he does, a musical sting plays for everyone nearby.
The log of Taggart, a Hunter who, well, hunted the Stalkers. It all starts out funny enough but the last log:
Lo.. Lo.. Log... Entry F... F.. F.. Fi... *pause* Henry... and its spawn.. killed my crew and the sadistic bastard chewed my hands off. I could see him smile. *Another pause* .. No.. Henry! Henry! Stay back! Henry! Ahhhh! MOMMY! MOMMY! MOOOOOMMMY! MOOOOOOOOMY! *Accompanied by chewing noises*
The concluding quip of the quest doesn't help, either:
You found Taggart’s missing chapter and, in so doing, discovered a soul-crushing truth: all the confidence in the world cannot prevent you from dying frightened and alone. But on the upside, you got PAID!
All of the player characters have a few different noises for when they're set on fire/corroding/being electrocuted. For the original four all of said noises are varying degrees of grunting in pain. Gaige, however, doesn't grunt. She screams in pain very loudly and very realistically. You get to hear a teenage girl scream in agony every time she's hit with an elemental weapon. It's...unnerving.
Lilith in "Angel Vision" after the game's Wham Episode. Unlike Angel, Lilith just looks like she's in agonizing pain whenever she talks to you like that, and she probably is. And she is, instantly regenerating in Hero's Pass from Jack, who is stabbing her, repeatingly.
Handsome Jack, while undeniably an evil douchebag, manages to somehow be funny with his sheer mania and trolling. However, once you clear Opportunity, his smug, taunting personality suddenly becomes threatening and serious, and his dialogue from then on becomes surprisingly sinister, particular his line when he sicks the BNK3R on you.
Handsome Jack (In a completely serious, low and seething tone) Now do me a favor...and die.
Worse is Handsome Jack's treatment of his daughter, which you learn from an audio tape in Fyrestone/Jackville. His sick, sick treatment of her...Not mention his real face. Pure Body Horror.
Bloodwing's death scene.
Several things Krieg says. When they say he's a Psycho, they mean it.
Krieg:I'm beginning to remember—STOP IT!Keep the memories down with a knife in its throat! Slash it until it bleeds thought juice across the dirt until it is absorbed intonothingnrrrsss...
Krieg:THE SILENCE! KILL IT! I'LL FIND YOUUUU! Quiet noises, and I'll STRANGLE the whispers out of you WITH A BONESAAAAAW!"
Playing as him is a strangely tragic and disturbing experience. Whoever he was before Hyperion got him is lost. He was irrevocably broken, turned into a monster by Hyperion. Krieg emerged from the experimentation as a Badass Psycho, insane with a need to kill. Krieg's former psyche was sent to the deepest depths of his soul and out of control of his own body. His other personality knows this, and has seemingly given up on ever recovering. A player rips their way across Pandora, occasionally hearing the sane part of Krieg quietly commenting on the action, in an utterly mournful voice. Being a Badass Psycho isn't as cool as it seems.
Even the names of his skins start to tell a grim story when you piece them together.
"I AM THE ONLY ONE LEFT" "I'LL NEVER GO BACK" "DON'T MAKE ME DO IT" "CAN'T CAN'T CAN'T DO IT" "DON'T STOP PLEASE HELP ME" "NO NO NO NO NO" "WHYYYYYYYY"
The penultimate boss battle of Assault on Dragon Keep. Having the person you've been trying to save turn out to be Evil All Along isn't exactly new, but when that person is being played by Angel, it becomes quite chilling.
Princess Angel: At last, I'm free...free to wreck my vengeanceUPON ALL THE WORLD!!
Becomes just plain sad when you realize that it's Tina who made her evil, in a desperate attempt to blame someone for Roland's death.
To make things worse, Angel stated that Handsome Jack tricked the last four Vault Hunters with Angel, and Tina made Angel into a Villain. In other words Tina knew she was a danger, and Roland payed the price. Tina made Angel as she saw her as: A lure.
Also from Assault on Dragon Keep, the first time you encounter a mimic. You've just finished cleaning up some fantasy foes, and are ready to open the nearby chest of loot OHGODWHATTHEFUCKISTHAT.
The quest where you have to carry a midget up to the giant fake dragon and set him on fire. Sure, he's going along with it voluntarily, but still, you're basically helping a guy burn himself alive out of devotion to a goddess that you know isn't actually a goddess.
Handsome Sorcerer in the last part of Assault on Dragon Keep. He gets so graphic that even Brick points that out.
Brick: Damn, Tina. That was graphic.
Tina: Don't hate the player, hate the game.
In fact, that WHOLE last stretch of the DLC is rigged with The Sorcerer going into gory details about what he and his soldiers are going to do with the queen! It even gives the vibe that this is timed!