There are doglike creatures called "kubrow" that can be encountered and fought. Players can also breed their own, which can be injured and temporarily 'die' for the duration of the mission.
A character has her nudes shared without her permission with her entire college campus, ruining her reputation and causing people to give her an insulting nickname.
Late in the game's main questline, a main character that explicitly acts as a surrogate mother to the child player character leaves them for an extended period of time, albeit unwillingly.
Cephalon Ordis mentions almost performing a sequence of “self-destruction”. It's heard while the Player browses the hidden lore from the memory Fragments.
In a cutscene from “The War Within” story, Ordis performs the same self-destruction sequence but the Operator (the Player's character) stops him from doing it.
If the player is defeated by an enemy called the Zanuka Hunter they will awaken strapped to a dissecting table before attempting to escape. Some Corpus levels also have captured NPCs who are restrained by wall-mounted contraptions.
There is the option to discuss religion with Lettie via a chat system. Other characters throughout the story reference the idea of gods and demons and hell, but not in any sort of concrete way. More so just the general concepts of them.
The nonbinary character, Flare, expresses to the player character what could be interpreted by some as body dysphoria. Other characters also express discomfort in their bodies due to the nature of the infestation and its mutations.
Some characters occasionally send messages to the in-game inboxes of all players talking about real-world promotions / sponsorships or changes to the game, albeit from an in-universe perspective. The fourth wall is even occasionally referred to directly as a "fourth-dimensional wall". No spoken dialogue mentions the fourth wall.
Creatures that greatly resemble sharks called lanx can be encountered in the submersible levels of the Grineer Sealabs tileset, all of which are located on Uranus. Lanx will only cause damage if bumped into.
In game, there's a seperate dimension known as the Void. Plenty of odd stuff happens in this dimension or because of it in the case of the Void leaking into the Origin System.
Upon defeating a boss, you're marked for death from a Stalker who will rarely spawn on your mission and try to kill you. Later in the game, you will also have Kuva Liches; the more you anger them, the more likely they are to spawn in and try and kill you.
While domestic violence isn't committed between two parents per se, the content warning to the New War quest explicitly mentions theming of emotional abuse, which is most prominent during its final encounter. The events of the encounter can be seen as domestic violence to those who have experienced it, especially seeing as how the abuser & abused are both most commonly seen as surrogate parents to the player character.
The horses seen in Duviri (known as Kaithes), while it is unclear whether they are already dead due to their skeletal appearance, are incapable of being harmed. At worst, they merely disappear to be summoned again later if their rider is attacked.
There are conservation missions available where the player is tasked with catching and saving various creatures. It is possible for the creature to be injured (for a reduced mission reward) or killed (failing the mission). There are also pest creatures that can be killed.
• Due to the combat nature of this game's environment, some animals and creatures are in extreme danger of combat fire in places such as in the Earth or open world environments.
• A gameplay feature known as “preservation” can get open world wild creatures out of these warzones, but it's more like a hunting type of preservation, where you shoot them down with a special hunting gun that fires tranquilizers and then you capture them. This may be unpleasant for some players. There's also the risk that you may fail while hunting and the animal would get hurt or even die.
• The “Howl of the Kubrow” quest, or generally obtaining a Kubrow companion requires you to smash a Kubrow den and steal an egg away from its family.
A talking creature that can be run into late in the game's story canonically has severe depression and has a tendency to be upset. This creature can be comforted once you reach the max rank with their group.
There are catlike creatures called "kavat" that can be encountered and fought. Players can also breed their own, which can be injured and temporarily 'die' for the duration of the mission.
Added late 2020 - the character Lavos has twin serpents that slither around his arms. There are direct references to these serpents in his museum entry.
Inaros can summon a swarm of scarabs to fly around him, and can make them attack enemies, though, they're so small they just look like specks and have no clearly defined features. Some enemies also look bug-like, though they aren't too common and the resemblance isn't that strong.
A character in the New War quest has another character force a kiss on her while she is incapacitated and visibly distressed/hurt. It is somewhat implied that things of a similar nature have happened off screen.
A character transforms into a 'sentient' chimera from the waist down, with visible viscera and a vestigial leg left behind. Body horror of many kinds is prevalent in the game and considered by many to be a major theme.
Enemies you face will, odds are, have broken bones when you're done with them, but there are no scenes that make it detailed and to my knowledge there are no sound effects or visual effects for bone breaking.
Well, not quite, as the player character can be forced back into their Warframe if they take normally lethal damage. That being said, the Chains of Harrow quest does depict a child/teen dying.
A few quests include a jump scare or two. Upon the completion of one quest, there is a small chance, every time you enter, for an apparition to show up somewhere in your orbiter for a jumpscare
• Harrow's Penance ability makes him flagellate himself, but only it drains his shields.
• Chroma's Vex Armor ability requires the character to get hit to get increasing buffs in armor and/or general damage. Players may resort to self-damage in order to max these buffs.
• The Hema weapon recharges every time by literally injecting it into your character and draining your health.
A certain character by the name of "The Man in the Wall" can induce anxiety attacks in players, due to the unexpected nature of the apperance. There is no known way to turn this off at the moment.
A significant amount of story involves a body-warping plague that is also the origin for one of the enemy types frequently encountered called "the Infested."
More abstractly depicted, but there is a pregnant warframe with a glass domed womb, and a ball of light inside of it, representing a baby. In her story/quest she gives birth to the child.
late in the game, while talking with certain characters as your player character, discussions of sex, masturbation, and various kinks can occur if the player wishes.
The Warframe Hydroid can transform into a wave of water, but the damage done is more from the force of the impact and water corroding enemies' armor. Previously he had an ability to transform into a puddle and drag enemies inside, slowly drowning them, but this was removed as part of his gameplay rework.
SPOILERS FOR 1999
As of the quest The Hex, a nuclear explosion does go off and is one of the first things seen when starting the quest. However, this is more of a vision of what COULD go wrong and the rest of the quest is spent trying to prevent this.
The finale quest ends with you ultimately succeeding in stopping the explosion.