-the ability to disembowel a person, bite their guts, then shake them around until you tear out the guts with your own teeth
Don't forget doing this, but before the actual shake-around you also ready an attack with a blunt and edge weapon such that you bash their skull in, knock them through the air, and then while they're dead in mid-air cut their head off to let the body skid and tumble across the ground or slam into their friends.
-being able to partially bisect a person around the waist (sometimes when you kill someone with a slashing attack to the lower body it says that its "partially severed from the torso")
I've completely bisected people, getting the "completely severed from the torso" messages, even gelded during this... somehow.
-being able to simply explode body parts by hitting them hard enough (I can understand how it works with hands or feet but how it would look like with an entire arm or leg I don't really know)
Ever seen the DBZ episode with Vegeta and the androids when he's first gone SSJ and is cocky, then 18 just kicks him in the arm and smashes it the wrong way, breaking some of his ribs too?
-gouging or otherwise cutting off all of a persons facial features, cutting off their limbs, disemboweling them and using fast travel to keep them alive
Somehow you can grab someone by the head with one hand and systematically remove their teeth, nose, tongue, ears, and gouge their eyes until they're pulp. You can pinch arms and hands and legs and snip them off, and of course travel away so they live.
-people literally melting from being fire or magma
I've got a dragon/dwarf hybrid I made which is when I learned that the last part of the dragon entry which sets the tissue temperatures also sets sweat and tears, which I fixed to stop burning my clothes off, but I left the spit in. I've been assassinating occupation administrators by spitting on them and watching them burn to death as they try to climb up the walls to get away from their own melting flesh, the whole time talking about "this isn't happening, help, save me!" and so forth.
-cleaving open heads or crushing them
Gotta love when you tackle someone and end up standing over them, so you stop and look at everyone else in the room, then matter-of-factly stomp their buddies head into gore.
Find a room full of goblins connected to the sewer, start jumping in and tackling them, punching them across the room (the 9.9 speed is just part of the full mod buffs in place at this point, I'm as strong as I can get without rolling over to 0.099 speed):
Course, it isn't always others experiencing the horror.
Sometimes it is even my own fault (knocked a goblin into magma, got caught in mist, tried to put myself out with booze... don't ask).
Later I got the dragondorf template working so I was swimming in the magma pool at a temple and my minecart was full when I noticed I could just pick up the magma.
After bashing a few dozen goblin skulls in with it, apparently it got so bloody that it cooled into obsidian.
The kills on it there are post-cooling.
I don't even know how I was carrying around a minecart full of magma one-handed, much less how it stayed together as I crushed enough skulls for it to become so bloodsoaked it solidified, but hey... there's violence, and then there's df violence.
Before I was just using the cart full of bodies (that weighed 8500 urists) to knock people across the screen.
This isn't even trying to be violent, this is just playing around taking out bandits and criminals.