The main character was emotionally abused by his father as a child, this is not shown often besides some flashbacks in the Iki island DLC, it is not shown in the main game.
And two other characters from the main game, who are a brother and sister, also described their mother as being alcoholic and physically abusive when they were children, but none of it is shown on screen.
In the DLC of the game, a major plot point is that a new tribe of Mongols are forcing people to take drugs which give them violent hallucinations, however there is no voluntary drug use.
Enemies will sometimes send dogs or falcons to attack the main character, and in some instances they will have to be attacked and killed, other times they can probably be ignored and left alone. They do not die in agony or gory detail, they die very quickly.
Wild animals such as bears or pigs may also attack the main character and other NPCs but they can be left alone almost entirely, sometimes there will be bears trapped in a cage in enemy camps and they can be released, if they are killed they also die quickly
The main character's horse also dies at the beginning of the third act of the game after being hit with several arrows and tiring after walking a long distance in the snow, it is a very emotional scene and some viewers may find it upsetting or traumatic
One set of collectibles are caged crickets, though they are only shown clearly in the menu. Some areas feature groups of dragonflies, fireflies and butterflies.
Several scenes show people being burned at stakes. Some enemies have incendiary weapons that will burn the player, and sometimes other enemies. The player at various points obtains various incendiary weapons as well.
A few abilities in game result in the player cutting limbs off enemies, including but not limited to the Ghost Stance. Late in game a character is found with all of their limbs amputated.
The player is able to bath in hot springs throughout the game world to upgrade their health and the character is depicted nude from behind while entering. Some areas also include partially undressed characters bathing.
There are no cops in the game as it is set in Kamakura period Japan and the closest thing to police officers are the Samurai, but they are shown accurately, not glorified. Oftentimes the game will point out that many samurai have failed to protect people and have abused their power on ordinary civilians.
(Spoiler)
At the end of the game, the main character's uncle requests to be honored with a warrior's death, in modern context this may be seen as an assisted suicide, but it is entirely optional and the player has the choice not to go through it. There is no gore, just a single stabbing noise
There are no planes in the game due to the time period, however at the beginning of the Iki Island DLC there is a Boat Crashing upon the shore, the main character and his horse survive the crash but are briefly separated