The Tres H***y Boys treatment of Angus can come across as a little too mean at times, and his reactions are pretty sad, though it is played for laughs.
[Spoilers] They are called out on this later and their relationship is deepened.
At the very beginning of the story, the boys come across Gundren and Barry's cart which has been raided by goblins and their horses slain. It is not given very much description.
[SPOILERS FOR THE HERE THERE BE GERBLINS ARC, THE ELEVENTH HOUR ARC AND THE STOLEN CENTURY ARC] The Phoenix Fire Gauntlet burns cities to the ground, and it is mentioned and spoken about in detail multiple times. People also die in explosions in The Eleventh Hour arc.
No real physical torture is exacted, but...
[SPOILERS]
In the arc "The Suffering Game", the main cast as well as some side characters are forced to remove their own body parts and physical attributes through instantaneous magical means.
The latter half of The Crystal Kingdom arc reveals that spirits are escaping/attempting to escape the Astral Plane. A few villains who the boys previously killed reappear as ghosts possessing robot bodies, and later multiple ghosts possess one vessel in a boss battle against "Legion"
[SPOILERS FOR THE SUFFERING GAME ARC] Magnus's soul is pushed out of his body, and his body is taken over by a lich. Magnus then possesses a mannequin's body.
There are scenes where characters are panicking/stressed and making rash decisions in result of that, as well as a scene where a character seems to be having a breakdown due to a revelation, but makes an exit before we can see it escalate. Also, in season 2 (Amnesty) a character explicitly goes into shock/a disassociative state from triggering their PTSD.
In the arc The Eleventh Hour, the character Roswell uses they/them pronouns, but this is only established in their second appearance, so for most of their first, the players (and DM) use he/him. Other mistakes are made throughout the arc. The most significant trans character, Lup, is never misgendered.
Several LGBT people die, however by the end of the story none of them remain dead *Spoilers*: in petals to the metal both Hurley and Sloan's die after Hurley gets poisoned by Sloane and Sloane uses the Gaia sash go turn both of them into a tree. They return in Story and Song as Dryads. This is the worst example of Bury your gays and Griffin has apologized multiple times for this as he didn't know about the existence of the trope at the time. -Taako, who is gay, as well as the other two PC's dies multiple times in the 11th hour when the three are caught in a time loop that resets every hour after they die. With the exception of the first time, these deaths are known to be inconsequenctial and at least one time they intentionally blow themselves up as a joke to do something more convenientally without having to wait. - in Stolen Century Taako and Lup, who is trans, also die multiple times in a similar way to the 11th hour, being resurrected at the end of the year just like everyone else. We are told that everyone died multiple times during the Stolen Century however the only time these two are actually described dying is once when everyone but Lucretia gets turned to stone. -Lup's deaths in the Stolen Century are mitigated since she and Barry created Lich forms so they could live after death.