A forest will be grown in his honour! I think you're right....and I guess that there would be pockets all over where the elemental types would collide. Your tragic Pangor being Life and Darkness? Or Earth and Darkness? The fairlands certainly need a bit of darkness injected.....perhaps a coastal cave network as well. I could also see Pangor on the other side of the crater, stalking the black beaches, collecting the skins of washed up corpses, so his dark forest origins could even lay deep in the weeping mountains!?