They have potent psychic powers that manipulate reality around them
I read once that this is why they paint their vehicles red. Because they believe that red makes it go faster, and with their latent psychic ability, the red ships actually DO go faster, because they believe so strongly in it.
I personally see “bloodline” as a specific, direct line of descendants through a certain genetic-based family, title, position, etc. Whereas a family tree is literally everybody you’re related to, directly or not.
EDIT: As an example, I have an uncle on my mom’s side of the family. He’s not genetically related to me; he married into our family. He also brought a daughter from a previous marriage, so she’s legally my cousin, but we’re not genetically related at all. They married into my bloodline, but they aren’tof my bloodline, if that makes sense. They’re part of my family tree.