So here's the explanation on what happened to those of you that want it. I might possibly maybe in the future make a fictionalized version of it, but for now this is just the boring explanation :)
My idea is that vampires where created by a mix of science and magic, a potion and a spell, a very long time ago in Atlantis. The person who did it linked the life force of a human to the Sun, the most inmortal and eternal thing he could think of (I think that would also explain why the sparkle in sunlight). However, as we know nowadays, stars don't live forever, so when the Sun died (our Sun, which was the one used for the spell) then every vampire ever made, since they were a consequence of the original spell, died with it. The hybrids were half human, so that saved them from dying, though of course they can't turn a human into a vampire anymore. Since they are unique they wouldn't necessarily become human, but they would lose the venom and changing characteristic.
The blood drinking and superpowers would have been just an unforseen side effect.
Let me know if you have other questions and I'll sen you a PM.
Thank you for reading!
AB xox