Mefisto in Onyx Book

This is the first Harlan Ellison novel I've ever read. I was pretty impressed with the plot, which involves the world's only empath being asked by a friend (and D.A.) to dive into the mind of a convicted serial killer she has fallen in love with to prove his innocence. Excellent plot twists, however, I didn't find the main character's voice entirely consistent. He was supposed to be a well educated black man from humble beginnings, and the African American colloquialisms Ellison sometimes employed felt a little forced and out of place. This could be because I just watched a documentary on Ellison and could only imagine his voice speaking all the lines. I also thought the ending was a tad neat and tidy for the bleakness of the first half, but the story really did grab me.