I'm the progenitor with two originals wives: Futa

10 original vampires' family's/Xenna/Kane

The 10 original vampires' families are the ones that Xenna aka Namamy daughter brought with her to the mortal world after leaving her mother, when she and her brother got into an argument about humans and demons while also being mad at their mother for her unwilling ness to act in the regards to either. Especial with all things besides the animals being made from her. What makes the 10 original vampires and Xenna along with her brother Kane special is they're with the highest purity of blood linage to her being that Xenna and Kane are directly born from her due to being self-born from her.

The 10 original vampires are next to having the purist of blood linage even though tied with another race, but the 10 originals were made from her blood that she created into vampires there for they weren't directly born from her like Xenna and Kane were.

Any vampire to be born from them would be original vampires keeping their linage original but once breeding with other non-originals happens and it sprouts forth an child their blood linage is not of an original.

So, if an original and another original were to have kids, they would be originals but if they were to breed with a demon or mortal, they're child or children would not be an original they would be known as synthesis. 

Essence/Percentage equivalence to rank

Essence comes from how pure your blood linage is and tells of what descendant it's from to connect you with the originator's blood line, so the higher the purity of the blood line percentage the higher chance your essence will be high. Even though it can still be weak despite having a high purity blood line, but there also chance of your essence being higher than the purity of the blood even though it mainly common when a synthesis is born.

Now the reason percentages are converted to ranks is because it tells the level on essence is at due to them being slayers that kill monsters, demons, and bounty hunting to live it more convenient to have their strength classified from what their essence percentage is equal to.

Essence percentage ranks

Originals vampire percentage ranking:

85%-87%-> C/B-rank

88%-89%->B+ rank

Favorite ones (synthesis)

90%-92%->A/A+ rank

Child of the goddess

93%-95%->S/SS-rank

96%->SSS-rank

10 human tribes ranking

80%->D-rank

81%->C-rank

82%->B-rank

83%->A-rank

84%->A+ rank

85%->S-rank

Human's favorite ones

86%-88%->S+ rank

89%-91%->Ss-rank

Child of the goddess for humans

92%-94%->Sss-rank

Favorite Ones

The favorite ones are generally the synthesis that born from cross breeding between the races as there also cases of originals and pure vampire, demons, and humans born as favorite ones, even though it's a low percentage of them being born as favorite ones. So, synthesis is the vast majority of favorite ones in the world.