History NightmareFuel / FafnerInTheAzureDeadAggressor

** And the effect shows. Canon literally FadesToWhite in Episode 17, and Mimika "turns" into a bowling ball-sized sphere after Episode 20. Now one wonder how others will become...

* The Fenrir mechanic in the Fafners. If a pilot has no way of escaping a Festum with their life, their last course of action is to blow themselves up along with the festum so that the Festum hivemind can't learn anything else about humanity from the fight. And as of Exodus, that might not even work anymore.

* When they were kids, [[spoiler: Soushi was almost assimilated by the festum. The only way to save him was to gouge out his eye where it had started, and Kazuki, being the only one around, was the one who had to do it]]. This ended up traumatizing him so badly that he blocked out the reason ''why'' he did it, and was left only with the memory that he was the one who [[spoiler: blinded Soushi]].
* The manner in which [[spoiler: Mamoru is killed]]. His cockpit is basically wrung out as it's crushed, with him inside of it. The only thing left is a twisted up hunk of metal that's seeping blood.

* The entirety of Right of Left. Pilots begin succumbing to the assimilation phenomenon, and those who are left have little hope but to eventually follow. And then the festum finally learn how to survive in water, [[spoiler: and Ryou (who is almost fully assimilated anyway) has to blow himself up at the bottom of the ocean right after his love interest disappears to make sure they don't find the ship or the island.]]

* By the time of Exodus, the festum have evolved and adapted so much that [[spoiler: three nukes isn't enough to take one out.]] Granted, it's a pretty big one, but still.
* Although it protected Emery and hasn't displayed any signs of hostility, [[https://40.media.tumblr.com/e64c1bb90a414001c4d78080e057a58b/tumblr_ni8lqf7L1k1qgl4zdo2_500.jpg this]] [[https://40.media.tumblr.com/453a5d412d9d9bb8c136614bb78e8c69/tumblr_ni8lqf7L1k1qgl4zdo3_500.jpg festum]] certainly looks creepy, standing there silently before disappearing.
** It's started attacking the island and each time it does they almost lose.
** And [[spoiler:the Walker is following the island all along, meaning that it can launch attack basically '''anytime''' it wants. ParanoiaFuel at its best]].
* Soushi has been attempting to [[spoiler: dismantle the Mark Nicht, which is starting to develop sentience and is currently resonating with Sein so that anyone who tries to pilot the latter is immediately 'devoured' by it. Nicht is sentient enough that it can stop the pain blocks from being enacted, and when Soushi continues to tear at the mech to get to its core (while inside, and very much feeling the pain of clawing through your own skin), it actually attempts to assimilate him. The only thing that saves him is the fact the he's part Festum now.]]

** And then in Episode 13 [[spoiler:it suddenly appears and throw the line [[ArcWords "Everyone is better be gone"]] during Kazuki and Maya's casual conversation]]. Cue JumpScare.
* [[spoiler: Yumiko]] gets crushed by a collapsing building, and all we see is a protruding hand and a splatter of blood.
* Each of the pilots who participated in the island's fight in episode 7 have started undergoing bodily changes that get worse the more they pilot. As Orihime describes it, this phenomenon is saving their lives from the assimilation process, but not necessarily their human bodies or minds. [[spoiler:Reo has a hole in his chest that gets bigger the more he pilots, Mimika is growing hardened growths out of her back, Sui is becoming more and more dense, Rina is borderline-comatose, and Seri has started assimilating everything she touches.]] Not to mention that if these kids go out of commission, there won't be anyone left to protect the island from Festum attacks.
** Now [[spoiler:Sakura and Canon also suffer from lower body temperature and lighter bodyweight]]. No one is safe among the pilots now.
** And the effect shows. [[spoiler:Canon literally FadeToWhite]] in Episode 17, and [[spoiler:Mimika "turns" into a bowling ball-sized sphere]] after Episode 20. Now one wonder how others will become......
* Episode 12 we see men got assimilated ''just by hearing parts of its voice through the phone''. Now you don't even need to stay close to them to get assimilated; they do it through their mind. ''They won't even let you use the Fernir in the progress.'' Think about that for a moment.
** Then in Episode 14 Festum learned to ''completely destroy a Fafner'' which is about to use Fernir, rendering the pilots' efforts moot. Yes, Festum LEARNS.
* After [[spoiler:pilotin Mark Dreizehn again]], Canon [[spoiler:gains the ability to forsee future]], which does aid the team in the immediate battle. But the scary part? [[spoiler:She saw ''graves for everyone on the island AND every Fafner destroyed and bloodied'' by just visiting Hazama family's grave, hinting that ''[[BadFuture this is a possible outcome for them]]''.]]
** To fuel further nightmares, [[spoiler:Kazuki's one-on-one duel with Azrael-type in Episode 15]] goes ''exactly'' like [[spoiler:Canon's vision]], so to show that [[spoiler:her visions]] are ''correct''.
** And in Episode 16 [[spoiler:Canon finds out she can't see the future about events after a certain date]]. The mere implication about it is horrifying for [[spoiler:a "fortune-teller"]]......
** ......Which is nothing when [[FridgeHorror it's revealed in Episode 17]] that [[spoiler:a "winning" future is possible as Kazuki finally comes back to defeat the Walker.....except ''[[EverybodySDeadDave only Kazuki returned and everyone else stay dead]]'']].
* [[UnfriendlyFire Combat Regulation Alpha]]. The Regulation had been built up for a while, but when it's actually put into action, ''fellow humans'' will become as dangerous as Festum around. Especially they can initiate it at anytime, against anyone, even when ''they're fighting on your side at the same time''. [[spoiler:Hiroto learned the hard way.]]
** Not just that, but at the start of [[spoiler:episode 14, the same episode where Hiroto is killed, a soldier is seen killing someone who went againt the Regulation. Even if you survive the battle, they will hunt and kill you for breaking it.]]
*** In ''Exodus''' Episode 23 [[spoiler:Maya ties Mark Sieben to a Neo U.N. sub and sets Fenrir for a sixty second detonation if ROE Alpha is not revoked. There are 11 milliseconds left on the timer.]]
* Just... Walker ''[[SlasherSmile smiling]]'' when [[spoiler:the shield around Tatsumiyajima island falls.]]
* The new [[spoiler:Leviathan]]-type. Just imagine a Festum that is [[spoiler:sixty kilometers long]].
* Episode 21 of ''Exodus''. Pilots succumb to the assimilation phenomenon AGAIN, and the refugees reach their destination with [[spoiler:around 5000 left, after 17000 died getting them there. Not just that, but ''another'' Azazel appears, and during the battle Kazuki's [[HighPressureBlood arm is assimilated]].]]
* [[spoiler:Mark Raison]] is the most powerful Fafner to date, [[spoiler:being able to assimilate Crawler using light without effort where Nicht couldn't do anything.]] It could, and most probably should, go under Awesome, but it doesn't. Why? It's pilot is [[spoiler:Jonathan Mitsuhiro Bartland, the Puppet. In other words, one of the most powerful villains in Fafner can assimilate ''anything''.]]
** [[spoiler:The Puppet program]] itself is also a NightmareFuel. Imagine that one day [[spoiler:you got your pre-established personality and life as a human got ''completely erased'', when you don't realize it until the very last moment]].
*** [[spoiler:ANYONE could be a Puppet. The only people it couldn't be are the residents of Alvis-and even then, anyone captured by the Neo U.N. (Kazuki and Maya) could be one.]]
* [[spoiler:Vagrant. It can use portals to attack and reflect attacks, assimilate other Azazels, is practically made of Nightmare Fuel, ''runs'' on Nightmare Fuel etc. It's also the cause of Raison's power.]]
* [[spoiler:Sui crying ''blood'' when trying to use his SDP to rip out Vagrant's core.]]
* It's Episode 26 and [[spoiler:Altair has arrived at Earth. The problem? Miwa-the stringest Esperanto-isn't strong enough to communicate with it and Prometheus reaches i first. Thankfully Altair is picky in who it wants to talk to.]]

** [[spoiler:The Puppet program]] itself is also a NightmareFuel. Imagine that one day [[spoiler:you got your pre-established personality and life as a human got ''completely erased'', when you doesn't realize it until the very last moment]].

[[spoiler:Sui crying ''blood'' when trying to use his SDP to rip out Vagrant's core.]]

*** In ''Exodus''' Episode 23 [[spoiler:Maya straps Mark Sieben to a Neo U.N. sub and sets Fenrir for a sixty second detonation if ROE Alpha is not revoked. There are 11 milliseconds left on the timer.]]