unDany, Blood Magic, and the Valyrian Sphinx

My response:

I LOVE that I discovered this theory through the end of year awards, and I have a few contributions of my own.
1. - If Shireen is sacrificed in the book to resurrect Jon, as some theorize, and is (kind of) alluded to in the show, that would make Jon the second "dragon". The first being Daenerys, if your theory holds. Would there then need to be a third at some point to make the third head of the dragon? OR
2. - Could "the dragon has three heads" be more literal? You have a dead person, a person that is sacrificed, and a (seemingly new) person that is resurrected. My only issue with this would be that there isn't a sacrifice when Thoros resurrects Beric, he simply breathes fire into his lungs and both are fine. But also Beric isn't exactly an improved version of himself like Daenerys is when she wakes, it's like they literally "woke the dragon" in her case, so maybe that's where the "blood" part of "fire and blood" comes in? The blood needs to be Valyrian.
3. - I see a lot of Summerhall stuff and Rhaegar was the last dragon stuff in the comments, but Rhaegar died a pretty normal death and didn't really do anything miraculous in his life, so I don't think Summerhall resulted in this kind of magical birth or rebirth for this reason: Magic hadn't yet returned to the world. It's stated pretty clearly that it's a special time when the glass candles start burning, etc, maybe all the attempts by Targaryens in the past (Aerion, Aegon V, Aerys II, etc) weren't crazy, they were just doing the right thing at the wrong time. Thoros's kiss of life working unexpectedly, Mel's magic getting stronger, glass candles burning, etc. Magic has returned now and dragons are waking.
4. - Do other religions work in a similar way? Is there a "earth and blood" equivalent with first men blood and some kind of sacrifice (like Craster's babies still are??) the Children of the Forest used to create the first Other? We know there used to be blood sacrifices to weirwood trees, Bran's weirwood paste might be a Jojen blood sacrifice, etc. If Euron knows the Drowned God works in the same way, and he's preparing for a massive sacrifice in the Forsaken chapter, we could be in for a much wilder ride than we ever imagined when we started reading this series.