Saurians as ancestors to the KaIm and Nephilim?

In an older post, I suggested making Saurians the same race as the KaIm. However, after thinking some more, I thought a further refinement would be to make them the ancestors of the KaIm. Rather than being wiped out by the KaIm, the Saurians wiped each other out in a civil war between the Black Saurians and the White Saurians. The White Saurians won and brought the Black Moon crashing down, but it was a pyrrhic victory that resulted in their extinction as well. While new KaIm were born from the nexi, the Saurians themselves were extinct.

What made the next generation so different from their predecessors? The Saurians existed in symbiosis, an elemental Onirim Pentacle and a corporal dinosaur body. The next generation of KaIm were born in spiritual form and used their innate mastery of the elemental fields to create bodies for themselves. The Ka from the deceased Saurians was recycled by the nexi to birth new KaIm, but they would never again be Saurians because their fleshy envelopes were gone forever.

What I liked about this is that it creates a causal chain of agency between the generations of Immortals, like sins being visited on the sons of the fathers. I may have more thoughts in the future...