A straight razor is given to a mental patient. As he screams "Get them off me!" he starts carving into his torso, trying to cut the maggots he is imagining out (at several points, it shows things from his point of view, bugs and all). His spilled blood summons the skinless Julia, and the two begin wrestling, and there is just blood flying everywhere. When Julia finally kills the mental patient, he vomits, to add to the Nausea Fuel.
Kirsty is driven to reopen the box again because she keeps seeing visions of her father Larry trapped in Hell after the events of the first movie. The visions are actually coming from Frank, who's hoping to trick Kirsty into freeing him from his Ironic Hell, a realm full of immaterial writhing female figures he can't sate his lust against. We never find out what happened to Larry, possibly a reference to The Hellbound Heart, where both Julia and Frank are dragged off to Hell, but Kirsty sees no trace of Larry's soul inside the puzzle box.
Make no mistake, Channard had it REALLY coming, but one can't deny his transformation sequence (bordering on Cruel and Unusual Death) is nothing short of terrifying: Julia pushes him right into the transformation chamber and he's immediately immobilized by four tentacles. A fifth one sticks four needles through his spine (anyone who had to endure lumbar punctures may feel extremely uncomfortable at the mere thought of it) and another pair of tentacles ties four metal wires around his head to the bone. In the meantime, blood and cerebrospinal fluid get sucked out from his body and replaced by what looks like blue blood. The last shot of pre-transformation Channard has a toothed tentacle munching on his mouth, muffling his screams until he disappears along with the whole chamber.
Pinhead's death is the most gruesome. The other Cenobites are impaled through the chest, dying pretty much instantly. Pinhead, on the other hand, has his throat quickly sliced by Channard, causing him to basically drown in the blood filling his windpipe as he gasps for air.
The Reveal in this movie that the Cenobites, the terrifyingly sadomasochistic Humanoid Abominations, were human. They opened the puzzle box like anyone else, but for some reason they were chosen to undergo what we saw Channard go through and were horrifically mutilated until they fit Leviathan's vision, and became his enforcers. Even worse, they don’t even remember their own humanity, thinking that they are nothing more then their God's servants.
Something of note. When Channard kills the Cenobites, they revert to their human forms. Pinhead turns back into Elliot Spencer, Butterball and the Female return to their human forms, and Chatterer... isa kid. What kind of desires did he HAVE?!
Supplementary material and stories reveal the young man was once a child framed for his father's murder by his own mother and put into the system. He ended up an underage prostitute who got twisted by these experiences and wanted to be ugly due to the "adorations" his clients constantly gave him about his "beauty". The Lament Configuration was his escape from that life and a means of gaining control over his life.
