If he’s going to rip something off then let’s mention the gold standards (I’ll exclude Black Sabbath from the list):
Sleep - Dopesmoker
Sleep - Holy Mountain
Saint Vitus - Die Healing
Candlemass - Epicus Doomicus Metallicus
Melvins - Lysol
Pentagram - Relentless
If you’re feeling adventurous and wanna downtune even more here’s some drone/doom:
Earth - Earth 2: Special Low-Frequency Version
Sunn O))) - Black One
