Nightmare Fuel / Sniper Elite

• Unlike most works that depict Stupid Jetpack Hitler in an awe-inspiring or awesome sort of way, this series also goes to great lengths to show the dark side of the Nazis having such wonder-weapons, with several of these weapons coming close to causing massive Allied casualties.
• Even the more relatively grounded wonder-weapon-free original taps into this, with limited ammo and health and tense deadly urban combat where death can come in an instant, Karl feels incredibly vulnerable in gameplay and a single enemy with an SMG catching you by surprise can end you.
• Dr. Wolff's Evil Plan in Sniper Elite V2. It involves launching a tabun-filled V2 rocket at London. Note that this is late in World War II, when Allied victory was only days or so away, and that the people there were already probably celebrating in the streets. That's already pretty unsettling enough, but to make it worse, he was doing this under Soviet supervision (having successfully defected just before Fairburne could get to him), and that this entire scheme was a False Flag Operation where the Wehrmacht would be made The Scapegoat to cover-up the incident. Had Fairburne not foiled the launch, it would have been highly likely that London would have been utterly devastated by the gas attack, with thousands of civilian casualties, and the Western Allies would have likely bought the Soviets' alibi, with them none being the wiser.
• General Vahlen's plans with the Ratte in Sniper Elite III, and for that matter, Vahlen himself. According to the accounts of several German and Italian officers, once Axis victory in North Africa can be assured, he plans on overthrowing Rommel, the German High Command, and even, Hitler himself in a coup. When this doesn't push through thanks to the Battle of El Alamein and Operation Torch, he begins having a slow, but very massive Villainous Breakdown, which involves him forcing his men to double their work on the Ratte prototype, and executing anyone for even making a slight complaint against it. Not someone you want to be assigned under, especially when your side is already close to losing.
• General Bohm's anti-partisan actions in Sniper Elite 4. He orders his men to ruthlessly slaughter innocent civilians and suspected partisans alike, and the evidence of his men's actions can be seen throughout the campaign, with dozens of men, women, and children herded and executed. It's no wonder that even The Mafia, who are stated by Sofia to be mass murderers themselves, oppose the Nazis and their Italian fascist allies without question.
  • General Bohm himself for that matter. For most of the game, SOE, OSS, The Mafia, La Résistance, and even the Germans and Italians have no idea what he looks like. When he finally reveals himself to Fairburne in the final level, he turns out to be none other than Weaver's contact Major Dorfmann. He then mentions to Fairburne how much he loves to pose as different individuals in order to get the intel he needs, saying that he can either be a man...or a monster. Thankfully, Fairburne knew immediately that "Dorfmann" wasn't trustworthy.
• The Deathstorm Downloadable Content campaigns have some pretty unnerving things, namely, Deathstorm itself. As the campaign progresses, it some becomes clear that Deathstorm is a Nazi nuclear warhead project. Should this thing have remained undiscovered, it's very likely that the Luftwaffe would have deployed it against the Allies during the Normandy invasion, with thousands of Allied soldiers dying from the effects of radiation poisoning.
  • The destruction of the project at the end of the 3rd mission, while awesome, is also pretty darn scary. An entire town is razed just from the malfunctioning of a handful of incomplete nuclear warhead prototypes. It helps to demonstrate how devastating the weapon would have been against the Allies should it have been completed.