Note: The following can be interpreted as myth or legend, and there are many variations and theories in the world of NI about how supernatural creatures really came to be. This seems to be the most accurate, but that isn't saying much. First is a list of demons and vampires from oldest to youngest. Afterwards is NI's "origin" story.
Species from Oldest to Youngest
The species in order from oldest to youngest, in theory, are:
- The Powers That Be /God and The First Evil (Buffy/Angel/SPN)
- Eve - "Mother of All" (SPN) & Leviathans (SPN)
- The Old One Demons (from Buffy/Angel)
- Angels (SPN)
- Humans
- Lucifer's Demons (SPN)
- Animinus Vampires (Buffy/Angel)
- Mortuus Vampires (SPN) & Ugenta Vampires (TB)
- Solemus Vampires (BH)
- Daeva Vampires (TVD)
In the Beginning
In the beginning there was what some call "God," or what some call the "Powers that Be " - an all knowing, omnipresent power. There was also "The First Evil " - an omnipresent malevolent power. Some people believe that the Powers that Be is God, some believe that they are a part of God, some believe that they have nothing to do with God at all. Either way, the powers on the side of "good" or perhaps, arguably, on no side at all.
But for all purposes, we will call the creator of all things "God." God made the "beasts of the earth," the Leviathans, a type of beast with serpent like features and Eve. Eve created all monsters, starting with the Alphas - the first of all species of monsters. The first Alphas are called the "Old Ones," or in other words, the oldest and purest demons of all time (from the Buffy and Angelverse).
The Old Ones & Eve's other Creations
The Old Ones ruled the earth for a very long time, some were worshipped as Gods, and they raged war, havoc and Hell on earth. Levianthans had their own hierarchy as well, with leaders and ranks.
Eventually, some were killed, some were banished to other (Hell) dimensions, the Levianthans were banished to purgatory, and some were sent to a demon graveyard called "the deeper well." Eve was banished to purgatory herself for this havoc - but not before she set into motion the ingredients (unknown to man or any record in existence) that would eventually make more monsters, including wereanimal species, Ugenta, Mortuus, and Solemus vampires (Note: solemus vampire lore states that thousands of years ago, someone made a "deal with the devil" to live forever, but they had to drink blood in order to do it. In reality, some form of Eve was to blame for the creation of solemus vampires and she was called the devil.)
Unfortunately, because whatever she put in place didn't give her direct and ultimate control over her creations, vampires and the like have major flaws and weaknesses, and are no where near the perfection of the pure bred demons she created.
Lucifer and Hell
Also, in retaliation, when the world was peaceful again, God created the angels, and eventually humans. Lucifer, one of the angels, refused to serve the humans and was banished from heaven to Hell, along with the power of The First Evil. The First Evil and Lucifer were at one point merged but Lucifer eventually released the First Evil out into the world of humans, as well as created demons of his own. In the midst of this, the Old Ones who somehow still survived breeded with humans to create the first Animinus vampires (vampires are called half-breed demons on Buffy and Angel), until the last of the Old Ones were banished/killed. From there Eve's "ingredients" to create more vampires, demons, and monsters unfolded. Some call it supernatural evolution. Some call it Eve's spirit working her magic. In the case of the Daeva's, the latter was true.
The Alpha Daeva
Humans ruled the earth since then. But during the middle ages, a man named Mikael wanted his family to be more powerful than a werewolf species that threatened them. So his wife, who was a powerful witch, called upon the power of malevolent spirits and nature to make them into daeva vampires. What she did not know, however, was that she was calling upon the spirit of Eve.