Another Asta Origin Theory

So, today I was catching up on the anime, and I just wanted someone to discuss some things and theories about how Asta was born. While I was watching Nero tell the story from her perspective in episode 124, I kept wondering that maybe Asta is born from a Devil and a Elf that felt in love somehow, and for nature things, and maybe because a son of an Elf and a Devil would be extremely powerful and dangerous, there is a curse or mutation that makes people with parents like that, to be born without magic. What do you guys think? Can someone that is more informed explain to me why that wouldn't be possible? I don't mind spoilers.