Nothing can compare to the nuttiness that can be tech death. Blast beats plus virtuoso riffing is simply candy to the ears. The only problem, if it can even really be defined that way, is that tech death is rarely “dirty”. I mean that in the way that old school death metal or thrash bands can be dirty. Playing things a little looser and dialing back on the production qualities while also turning up the distortion is very rarely in the playbook for tech death bands. Fortunately, the fans of dirt have Revocation, a band that consistently blurs the lines between thrash and technical death metal. The Outer Ones is a great example that bands can play things a little loose while also being technical masters of their instruments.
Few things in metal go together better than thrash and black. Black metal essentially evolved from thrash when the two were initially entwined in the first wave, and the second wave embraced some aspects of it via a full rejection of death metal as “fake”. While that may seem like an extremely subjective reason to disregard an entire group from your community, it did push the two subgenres closer together. Now we have a host of bands who combine these elements to push forth a new extreme metal, and Black Fast is doing a lot to bring the two ideas closer together.