"Metal-Rules.com" considers Mercyful Fate's first two albums to be the greatest extreme metal albums of all time. Do you agree?

Even though I like Mercyful Fate and King Diamond, I think it's a bit of a stretch to consider these two albums as "extreme metal".

I know that many musicians were inspired by these albums, but with the exception of the lyrics that address satanic and occult themes, there's nothing shocking or out of the ordinary about the songs on these two albums.

Not to discredit them, of course, especially Don't Break The Oath, which I love, but do you think these two can be considered extreme metal?