To be honest, I know too many wiccans not to be annoyed at yet another "evil witch" portrayal.
I know a annoying number of wiccans and I scoff at them just as much as I scoff at myself (and everyone else for that matter) so, personally, I'm inclined to find your annoyance irrelevant. Besides, the difference between witches and wizards is that wizard has a "Z." Given that, and that we're playing DFRPG, if you're going to get annoyed at an ill-aligned caster, you might be playing the wrong game.
Belial666, Well you got across the point that this character is evil, old and a ritual using caster of some flavor or another (maybe blueberry? Kind of tart but enjoyable all the same?).
Question, though. Are you the DM or a player? I mean, is this an NPC or are you playing the blueberry? If you're dming then when will the players see all of this happen and not... well, do what they do best and screw up your story? Personally, in my games, I can't even get a half decent evil monologue out without a wannabe Dresden player interrupting with something he/she thinks is witty (sometimes they are and others... just sad...).
If you're playing an PC doing this, however, then practice it first. Hell, don't be afraid to have notes in front of you when you say it. Why? Because it's pretty long and with PLENTY of opportunities for derailment of your session. #1 problem in any tabletop game I've ever been in is ALWAYS derailment. To prevent that, have things rehearsed, ready, and keep things fluid as can be. If people start to interrupt out of character, talk over them and make it clear that you're going to recite this to completion and take questions after. If people interrupt /in character/... well... then just good luck.
Anyway, other than that, flavor wise it's cool. A bit dramatic but I think that's what you were going for, unless I'm mistaken.