Note: some of these words in here should have accent marks and so such but I'm not sure how to do that so sorry in advanced)
Well if you are looking to track down a Demi in folk lore you haven't very far to look. There is actually a Demi in the Christian bible you more than likely overlooked.
Since a Demi God is the child of a god and human or angel and demon.
Nephilim I want to say is the love child of a Angel and a human, or an angel and an angel. I'm told the reason that a match between a angel and a demon do not produce a Nephilim is because apparently an angel evolves into a completely new creature when it becomes a fallen angel to assure that it cannot change it's mind to return to it's former glory latter on in life. As some kind of curse or punishment from god. However I have not completely researched the subject.
Jesus probably wouldn't make your list at the first though, but he really is one. He's part god and the child of man. Making him one of the first real Demi ever recorded in history. (for those of you whom consider the bible a history book of sorts.)
One of the other more famous Demi which comes right out and says he's one I think(please don't quote me on that I'm not sure haven't looked it up in quite a while), is Hercules. He's the son of Zeus and a mortal woman. (which at the moment I can't remember the name of.)
Gilgamesh is also a Demi God, as the great king of Babylon he was two parts god and one part man making him a Demi as well. It's also rumored that he was the master swordsman of six swords, then again he did have six arms, but that's another story.
Since Mirravin is a Demi God I've done a bit of research on it for rping and book writing reasons, so I hope this is helpful in some way.
I think there are more but I can't think of any more at the moment. Does that count as the two or more you were looking for?
just for giggles, someone mentioned giants, Jotunn are the norse giants or giant gods. Loki being one of the better known ones. Giants are also mentioned quite a few times in the bible. I'm gathering we all know the story of David and Goliath, and one of the other battles which I want to say Jacob (Might be him but it's one of them at any rate.) lead an army guided by god to slay giants in another land or something of the sort.
The flood theme is also in the bible, we all know about Noah and the ark.
I can also give you a list of races and how they would effect any folklore they may be associated with. I might also be able to help with basic plots and natural disasters such as Pandora's box.
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~Once I knew who I was, until I met someone who knew me even better.~
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