Morbid Saint had some pretty harsh vocals. I don't see why its important to hear the lyrics in music this extreme. Perhaps poor example using Bathory but how about Overkill? Oh and Bathory best stuff was what he did from 1986-1990 IMHO. Also a lot of these bands were around before or at the same time as Metallica.
This came out the same year as Kill em all. Its considered punk but it shares a lot of elements with thrash. Its heavier, faster, and much catchier than Kill em all.
https://www.youtube.com/watch?v=p2pYl_vYiyc
Antisect?
Humm....it is WAY heavier. Too heavy for me.
Ok....I can follow you with Overkill. A lot cleaner vocals. Horrorsope is not bad.