Zephyrus
Tyrants and Slaves
Image is irrelevant. And even if it were, Sabbath was still had the darkest theme going on in the very early 70's (along with Alice Cooper).I would agree with the latter and disagree with the former. Sabbath always stuck with the hippie aesthetic - fringed jackets, goofy facial hair, and oversized Christian religious emblems.
As for their sound, it was an occasionally happy accident, rather than a consistent and deliberate application of a more focused set of ideas.
There's not a single "happy" song on Paranoid, which came out years before Rocka Rolla.
But even their "metal" songs tended to veer off into other styles and genres in parts.
So did Priest and most other early metal bands.
It's possible Opeth might be a metal band, but they ain't much of a metal band.
Their heavy parts are undeniably metal. Progressive metal, that is.
The vast majority of it placed on albums released long after the band's archetype-shaping and genre-defining classics, or on the band's first album, which was a definite work in progress (and included several cuts whose origins go back to '72 or so).
This pretty much contradicts your argument that Priest was the first "consistently" metal band.
Besides, Paranoid, the first "consistently metal album" came out in 1970, preceding Priest's first recordings by two years.
I admire your effort to defend your perspective, but the fact is you're plain wrong. Now I'm being nice to you because others would come in here and make you wish you've never been born.