The most punishing is Death Metal, Grindcore, and Black Metal. For instance, i have good friends in these bands (the Blame God stuff is free to download if you want) with new releases this year. Both bands are in the death/grindcore genre.
Blame God
https://blamegodusa.bandcamp.com
No/Mas
https://nomasgrind.bandcamp.com/album/raiz-del-mal (1st record, new one out at the end of the month)