Annihilate has never been slang, and it's not a word for a crime, or a slur, or anything. It doesn't fit the examples
Annihilate means complete and utter destruction, and it is sometimes used to refer to the overpowering of an opponent in a game. The great thing about this is that you can put any term in there that refers to an act of extreme destruction and everyone will catch your drift, however if you use a term that is not strong, people will not understand it. It is not a term for a crime, but if you were to literally annihilate someone you would do something like cremate them until there was nothing left (you could call this a "holocaust" I suppose). I don't see why rape would lose its power as a term when other terms do not have this happen to them. Gay only lost its power as an insult because we stopped considering gay people to be bad, and similarly I think rape would only lose its power in slang if we considered it not to be bad.
As for God and Jesus, those specifically become slangy oaths because of the prohibition on using them. The most interesting example of this is probably Quebecois profanity which is almost entirely based on various items or practices of the Catholic church, because Catholicism once held a massive amount of power and using these terms in such a way was a jab at that which was considered holy.
I think the difference with holocaust is how the word has become conflated so much with the Holocaust, that it is impossible to separate the two. With a capital H, Holocaust is not a term that can refer to a general word, but is instead very specific. It's the same reason I think saying "I worked like a slave" is not problematic whereas saying "I worked like a black man in the cotton fields" is. One is referencing a specific historical event, one is referencing a general practice. So by extension, I would say "I'm going to rape you like you're a nine year old Oprah Winfrey when we play Call of Duty" is not generally a good thing to promote as a figure of speech (wow that was a dark metaphor, even for me). Specific historical events tend to not become exaggerated whereas general ones do.
By the way, I like this spoiler thing, but I looked around and couldn't find out how to do it on here. I'd appreciate if you'd be so kind as to enlighten me.
