a lot of promise here. vowels are definitely there, but if you want the deathstep sound you should play more with the phase modulation on the heisenberg to make it more aggressive. post processing is extremely powerful yes, but phase modulation is how you get that gnarly aggressive sound.
There's also a lot of noise from the get-go. you could "simplify" your sound by taking a very distorted/compressed square wave and fading in the sound from that.