Repeating the consonant in many words in a sentence or phrase

Solution 1:

The technique itself is called alliteration. I'm not sure what I would call an alliterative sentence other than, well, an alliterative sentence. Wikipedia has an article on alliteration, listing quite a few examples (and mentioning V for Vendetta).

Solution 2:

I agree with RegDwight that it's alliteration, surely, but I would put it down more as a verbal tour de force, similar to Cyrano de Bergerac's coruscation of repartee in Rostand's play of the same name. When he is insulted by an oaf, who tells him he has a big nose, he responds with a speech that purports to be an 'assistance' to the oaf but is at once a profound mockery and a demonstration of how much better a verbal duelist Cyrano is:

Ah, no, young man, that is not enough! You might have said, dear me, there are a thousand things ... varying the tone ... For instance ... Here you are: — Aggressive: "I, monsieur, if I had such a nose, nothing would serve but I must cut it off!" Amicable: "It must be in your way while drinking; you ought to have a special beaker made!" Descriptive: "It is a crag! ... a peak! ... a promontory! ... A promontory, did I say? ... It is a peninsula!" Inquisitive: "What may the office be of that oblong receptacle? Is it an inkhorn or a scissor-case?" Mincing: "Do you so dote on birds, you have, fond as a father, been at pains to fit the little darlings with a roost?" Blunt: "Tell me, monsieur, you, when you smoke, is it possible you blow the vapor through your nose without a neighbor crying "The chimney is afire!"?" Anxious: "Go with caution, I beseech, lest your head, dragged over by that weight, should drag you over!" Tender: "Have a little sun-shade made for it! It might get freckled!" Learned: "None but the beast, monsieur, mentioned by Aristophanes, the hippocampelephantocamelos, can have borne beneath his forehead so much cartilage and bone!" Off-Hand: "What, comrade, is that sort of peg in style? Capital to hang one's hat upon!" Emphatic: No wind can hope, O lordly nose, to give the whole of you a cold, but the Nor-Wester!" Dramatic: "It is the Red Sea when it bleeds!" Admiring: "What a sign for a perfumer's shop!" Lyric: "Art thou a Triton, and is that thy conch?" Simple: "A monument! When is admission free?" Deferent: "Suffer, monsieur, that I should pay you my respects: That is what I call possessing a house of your own!" Rustic: "Hi, boys! Call that a nose? You don't gull me! It's either a prize parrot or a stunted gourd!" Military: "Level against the cavalry!" Practical: "Will you put up for raffle? Indubitably, sir, it will be the feature of the game!" And finally in parody of weeping Pyramus: "Behold, behold the nose that traitorously destroyed the beauty of its master! and is blushing for the same!" — That, my dear sir, or something not unlike, is what you could have said to me, had you the smallest leaven of letters or wit; but of wit, O most pitiable of objects made by God, you never had a rudiment, and of letters, you have just those that are needed to spell "fool!" — But, had it been otherwise, and had you been possessed of the fertile fancy requisite to shower upon me, here, in this noble company, that volley of sprightly pleasentries, still should you not have delivered yourself of so much as a quarter of the tenth part of the beginning of the first ... For I let off these good things at myself, and with sufficient zest, but do not suffer another to let them off at me!"

For the character of V, I feel the alliteration is not the object of the exercise, it is merely the vehicle. He is intent on displaying verbal prowess to mock, to bait, and to show how much smarter he is than his opponent.