I will keep this shortish.
It seems I percieve 'energy' or something in things from time to time. it just happens. It seems that the concepts of the dannan and the sidhe carry like yet differing 'energies" or whatever they are. I first noted it in stories, then pictures of places, then when I finally stumbled across otherkin...in some people claiming to be dannan. sidhe and/or fae.
The "energy" or whatever that seemed the same within dannan and sidhe concepts is also seemingly carried by the nephilim concept. It is my wild hypothesis, based on other wyld hypothesis (plural?), of migrations of certain groups out of the Middle East and across Northern Europe, and the energy thing above, that the Dannan and Sidhe are a descendants of the Nephilim. Groups from the mideast went elsewhere, isolated, and changed. This will forever remain at the stage of hypothesis because i cannot empirically show this in any way shape or form. Que sera.
That is why my kin type thingy says "Nephilim to Sidhe." It seems my energy jives with the Sidhe variety. Additionally, after years of prayer, literally, to YHWH, the answer is that I am one of those things, "nephilim to Sidhe," or whatever they are. I really don't think it's a big deal. My hypothesis could mean, depending on other migrations, that a whole heck of a lot of people descend from these lines. On that note, no it's not all bloodline IMO, but has a spiritual component as well. However It interests me enough that I will come to places like this and yak about these kinds of things.
To close this up. I am a student of Geology emphasizing in paleontology. I also have interests in physical anthropology, paleoclimatology, and actually hope to do grad work in the area of paleoecology. I am a former Marine. i like dogs more than cats, I like my red meat, I like my Alaskan Amber, Guinness, Pacifico, and Killian's Irish Re. I like berries, CSI and reading about theoretical physics even though it hurts.