Symbolism, Imagery, Allegory
As you've probably noticed, The Count is a strictly hands-off kind of guy. He never kills anyone, never stabs, shoots, or strangles any of his enemies – even though you can tell he really, really wants to sometimes. The one person he comes closest to killing actively is, actually, himself, back when he was a lowly prisoner named Edmond Dantès.
That said, he's perfectly willing to look death right in the eye, to watch heads get chopped off, to let people – and there's really no way to put this delicately – blow their brains out. This raises a big question: Why doesn't he kill his enemies himself?
Over the course of the novel we see death come in a variety of costumes: apoplexy, poison, pistol, sword – and, in perhaps the single most memorable instance – a big club and a large knife. That last one sounds pretty crude and pretty cruel, yeah? Well, it is; but it's also highly ritualized and regulated. It's called la mazzolata. Derived from the Italian mazza – mace – what it comes down to is being beaten to death with a big club. And then some. Here's the scene as related by Dumas (warning: this is seriously gross):
Meanwhile, the executioner had taken up his position on one side and raised the mace. Then, on a sign, the two assistants stepped aside. The prisoner wanted to get to his feet but, before he had time to do so, the club struck him on the left temple. There was a dull, muffled sound, the victim fell like a stricken bull, face downwards, then on the rebound turned over on his back. At this the executioner dropped his mace, pulled the knife out of his belt, cut open his throat with a single stroke and, immediately stepping on his belly, began as it were to knead the body with his feet. At each stamping of the foot, a jet of blood spurted from the condemned man's neck. (35.136)
Hard to read and, one supposes, much harder to watch. Albert and Franz certainly can't handle it. But the Count can. He watches, seemingly unaffected. But that makes sense: he's seen a lot of things in his day, and he's worked hard to make himself impervious to, well, emotion. That said, what are we supposed to make of the crowd? The Count himself tells Albert and Franz "there is no more interesting spectacle in life than the spectacle of death," and yet that can't really account for the "laughter, booing, and joyful cries" which come from the waiting crowd (35.103-104). Interest, after all, is different from joy, and even after the execution is over the mood is, by and large, joyful. And seeing that joy, we can't help but feel horrible.
But wait! Here's where Dumas has us. Over the course of the book, he reminds us over and over again how interesting death really is, and how interested people are to see it. So, yes, Dumas shows us the brutal spectacle of la mazzolata, and stages the key meeting between Luigi Vampa and the Count in the Colosseum, a place where thousands of ancient Romans watched thousands more die in countless, brutal ways. He also gives us prime examples of a different kinds of deadly spectacles: the duel and the "assizes." That first one is pretty self-explanatory: sure, dueling has a lot of rules, but it's still a spectacle, and no matter how much you dress death up, it's still death. In the second case, the deadly aspect isn't as quickly apparent. But think of it this way: why do people come to see Andrea "Benedetto" Cavalcanti get his day in court? Because they want to see the look on his face when he's condemned to death. It's as simple as that. And as for us, the readers? Well, we're waiting the whole time to see the Count of Monte Cristo get his revenge, and we wouldn't hold it against him if things got a little bloody, now would we?