There are some intense scenes, and some streams do have a TW of derealisation.
Though not explicitly shown, one characters tortures another over the course of months with his various "tools". This is very disturbing.
A character attacks another with a pair of shears. The other runs from him, laughing, but gets injured all the same.
In multiple instances, characters are brutally beaten to death.
Around half of the characters spiral into deteriorated mental states, often suffering from derealization and bouts of insanity.
The Butcher Army is quite frightening. The four of them wield axes and wear aprons with blood splatters on them.