Cool sub! What do you think epic metal means?

I've just had a spike of interest in the genre, and I made a thread in r/metal that got barely a couple of useful replies, so my interest is still largely unsatisfied.

Does epic metal have a claim as a real genre? Or is it just a specific feeling/style that can occur in any genre? Something in between?

Like I said, I've barely gotten into it, but my experience with epic metal is that of viking-era Bathory, Atlantean Kodex and While Heaven Wept, with some possible contributors in my trad/power metal collection. It generally includes grand, symphonic, atmospheric and majestic themes, and song structures that go through a journey, with long rolling riffs and operatic vocals. I'm undecided as to whether it is a real subgenre (of trad/power/doom) or it's just an attitude/description. That would probably depend on whether there's enough bands in the scene to wear in a groove.

Is Atlantean Kodex typical of epic metal or is epic usually more straightforward power metal like seems to be posted here? Cause I'd really like to hear more like them most of all.