I can improvise rhymes very well and am good at being mean to people but I have so little business rapping and my voice would sound terrible with it enough to negate it, if anything cause I just wouldn't have.the confidence necessary. I'd be really conscious about not doing a black voice, not sounding like Eminem or the beastie boys etc. I would be booed and sent to die.
I can't improvise to save my life nor do I possess any sort of lyrical talent. Also when I'm nervous, I have a hard time raising by voice above a hushed mumble.
So I don't think I'd do very well.