How to Make a Zombie Screech for Hard Techno in Vital

I start out with a lot of voices, detune and more detune range, and maybe take the stereo unison down a bit. Then a little bit of pitch automation, with the pitch attack and sustain going down.

Now go to the matrix and add Random 1 to the global voice transposition. Make it bipolar so it hovers around the center, change it to seconds, make it super fast and increase the amount.

Add distortion on hard clip and then a filter. I just use a band pass and focus on the mids, with the envelope on it so it goes down a bit too. Take the mix down a bit and add drive.

We can make this way more dirty by adding a phaser in front of the distortion. You can add a compressor, but I only like the single band, it's a bit less aggressive. Then a delay and a lot of reverb, and you can change the voices if you like.