Nightmare Fuel / Avengers: Age of Ultron

• Tony Stark's Nightmare Sequence, where a fleet of Chitauri troops moves towards the Earth because all the Avengers stand defeated, with even the Made of Indestructium shield of Captain America split in half to symbolize the defeat of Earth's greatest heroes. Rewatching the scene while deeming everything as Foreshadowing of what the confrontations with Thanos's forces would be doesn't help.
  • The nightmares of the other Avengers aren't much better, either. Steve's dream includes a party post-World War 2 with graphic shots of bullet holes on patrons. Thor's dream shows a blinded Heimdall and the destruction of Asgard, with Heimdall going on an insane ramble about Asgard's destruction. Natasha's dream, however, probably takes the cake out of all of them, showing her tragic past with a close up shot of Nat's surgery that rendered her infertile.
• At one moment, the Avengers are partying and having fun, the next a shrill whine is heard, coupled by an ominous groan from Ultron, who stumbles up. Imagine you and some friends are having some well deserved down time. You're chilling at one of your buddy's houses, eating takeout and doing a ridiculous dare for shits and giggles. Then some misshapen, insanely creepy thing (the scrap-heap Iron Man body is very deep into the Uncanny Valley, as not only it's so damaged it looks borderline zombie-esque, but it moves with limping and jerky movements) comes out of his basement and tries to kill you. The sheer Mood Whiplash could break your neck before it gets a chance to.