SEED was the first Gundam series to be broadcast in the 21st century, and to celebrate, the producers apparently decided to up the gore and horror content beyond anything previously attempted. As a result, Gundam SEED is one of, if not the darkest incarnation of Gundam (even more so than the already extraordinarily dark Victory Gundam, which says a lot).
Unmarked spoilers below.
- The ruins of Junius Seven are pretty gruesome, as to be expected of an area destroyed by a nuclear attack. 243,721 civilians died, and a flashback is shown of said nuclear attack, in which the damages to the colony cause it to break open and people and buildings are sucked out into space. The ruins are implied to be a lot worse than shown, but one scene shows the corpse of a mother still futilely shielding her baby's body even after they've been drifting in space for nearly a year.
- In a fit of rage, Yzak Joule destroys a spacecraft carrying Heliopolis refugees including a little girl that befriended Kira, all because he mistook it for a fleeing enemy shuttle. This scene became more disturbing in the HD rerelease of the series where we see the people inside the spacecraft for a second before being consumed by the explosion and dying.
- Nicol Amalfi's death, in which his attempt to save Athrun gets him bisected by Kira's massive beam sword, and the camera cuts to him screaming as he is sliced in half at the waist. After this, he has enough time to tell Athrun to run away with the sword still in his gut before blood fills his visor (head or organs burst open from the heat of the beam?), and his Gundam explodes. In addition, the next episode has his charred corpse seen by the others.
- Tolle Koenig's death is pretty gruesome too. Tolle's attempt to help Kira by flying in with a Skygrasper backfire horribly as Athrun throws the Aegis' shield at him, and Tolle is left in shock for a few moments before the shield smashes into his cockpit and rips his head off. It's even worse in the HD Remaster, where the original's freeze frame of the Aegis' shield colliding with the Skygrasper's cockpit and Tolle's head falling off towards his side is now fully animated, treating the viewer to a scene of Tolle's head ripping off and flying into the screen, with his horrified expression barely visible through his visor.
- The Cyclops self-destruct system (a high-powered microwave weapon) and gamma ray Kill Sat GENESIS. Microwaves heat water, and given that the human body is about 60% water by weight, you can imagine what it does to people caught in its area of effect. GENESIS is basically Rule of Scary. During its first usage, we are treated to a scene of a ZAFT soldier struggling before his body expands and his visor is filled with blood as he explodes, with a split-second shot of some of his ribs and his torn-up intestines flying out of his mutilated carcass. When it's fired into the Earth Alliance fleet in episode 48, we get to see the crews of the ships screaming and writhing for about a second, as their space suits expand and pop. It's even worse when the weapon hits an Alliance lunar base and space city, as we get to see several Bridge Bunnies at their communications stations, clutching at their chests before blood sprays from their mouths and nostrils, and then they burst like balloons. And due to his Villainous Breakdown, Patrick Zala was planning to use it on Earth.
- The end of the Battle of Panama, the ZAFT soldiers, still enraged about JOSH-A, begin killing the surrendering OMNI prisoners. The screams of the helpless soldiers getting shot up by GINN rifles and small arms is pretty sickening, along with a few images of their mutilated corpses for added effect.
- Mendel, the birthplace of the Ultimate Coordinator (Kira) and Al Da Flaga's defective clone (Rau). The blind ambition of the scientists led them to basically slaughter children For Science!, and the still functioning artificial wombs, still showing the embryo ultrasounds, is just sickening to the core. It doesn't help that it's Rau Le Creuset who is narrating just what went down here, managing to make himself look more like a victim than a villain, once he recounts how he was born.
- Rau Le Creuset is one of the most chillingly realistic Omnicidal Maniacs ever presented by a TV show. Rau's horrible life caused by his abusive father and Clone Angst convinced him that Humans Are Bastards and that he must put everyone out of their misery, along with himself. The scary part? He is partially correct. Considering all the racism and blind hatred fueling the wars (which both sides are aware of and DEFEND as virtuous, especially at their highest levels of authority), he has a very good claim for arguing his point. And it isn't even that he's blind to the capacity for good in humanity: he acknowledges virtue and idealism when he sees it, he just doesn't believe there's anywhere near enough of it to counteract the evils of humanity.
- What is more horrifying is that Rau failed to realize what Kira did: that his twisted logic of wiping out humanity instead of trying to help them advance and learn from their mistakes only made things worse, and the fact that he was not any better than the evil he had often criticized. In the very third episode, we see him opening fire on a group of unarmed teenagers, Kira's friends, who only survived because Kira blocked the bullets with his Gundam.
- There's also his return to the Vesalius after his confrontation with Kira and Mu. He returns to his quarters in extreme agony, wolfing down a handful of pills, snarling in unbearable pain, and very O.O.C. Is Serious Business, growls orders at Ades. And then, after a few more seconds of panting...he snaps back to normal and addresses Flay, who saw all that, and yet acts as if none of that display even happened. We already saw a hint of how fucked up his physical state was when he was in bed at home, also in extreme discomfort in his sheets, and even rolling off his bed, but no one probably ever imagined it was this bad.
- Azrael's final Villainous Breakdown is pretty nightmarish. Finally losing the last bits of whatever sanity he had left, Azrael holds up all of the Dominion's Bridge Bunnies at gunpoint to make sure they'd follow his orders while screaming like a maniac, beats up Flay when she tried to rebel, shoots Natarle four times after she managed to get her subordinates away from him, and prepares to fire the ship's cannon at the Archangel while twitching.
- After the Dominion is destroyed in the final battle, it seems that the Earth Alliance is out of the picture… except for one last pilot. It's Clotho, unable to return to his ship for the Psycho Serum required for him to function, and we get to see the full extent of the serum's withdrawal symptoms; twitching, writhing in pain, going Laughing Mad, and the skin around his eyes turning purple.
