Okay, here's the last riff of the tutorial.
As mentioned before, do your best to have your left hand fall on the strings during the rests. This definitely helps your rhythm playing to have a tighter sound.
First, we build up the riff playing a D# diminished chord. After that, we'll go straight to the chunky palm muting on the bottom string. The first time through, it's all palm muting, then the 2nd time through, loosen up the playing a little bit and let the notes ring out.