Very nice beat, I really thought it flowed with the "dark/evil" theme you are looking for
Nice choice of synth, reminds me almost of Super Mario 64 - Bowser's theme track which gives the same theme.
I really like it!
There's basically 2 things that I might have done to give the song more power:
I felt like the reverb on the drums were a little heavy for me (too over powering) and it took away from the sound
and EQ on the main synth I felt needed to be worked on, kind of like making it more sharp specially with the distortion already in play. With making the synth more on the sharp/higher end if you wanted to then balance that with a low end bass (3xosc should do the trick)!
Other than that I felt you nailed the dark/evil theme with the instrument choice and structure!