Meet TriXx, a rapper who has spent the last five months learning to perform Eminem's Rap God faster and faster and faster, with the hope of getting Eminem himself to comment on one of his videos. As far as I know, as of yesterday, when he posted his latest video claiming to be rapping at 200% speed (commenters quickly pointed out that he was faking it), Eminem still hadn't taken notice.
Even though the 200% video was faked, I do believe the rest are real. See for yourself and decide. Here's Day 1, when he starts. Day 5 is at 120% speed, and Day 10 is 145% speed, which is pretty much where he maxes out. And here's a compilation of the whole process.
If these performances are actually real, I'm impressed by his rapping skills. My mouth hurts just watching him!