User blog comment:Crimson Marauder/Third Progenitors Theory???/@comment-25942629-20151108131108

I've wondered about that myself, although I didn't particularly think of Lest and Krul. I thought it would be funny if Ferid were one and that was why he was so interested in it. Asura's response to the seraph part trying to take over Yu most recently makes me doubt he was one, and it's unlikely Krul would be one and not him.

However, the series specifically talks about a seraph "gene." Since neither Yu nor Mika mentioned their parents trying to kill each other but only trying to kill the children, I figured they most likely got this gene from genetic modification instead of by inheritance. If they inherited that gene, then one of their parents would have to have it, too. If genetic modification were used, then this technology would be quite new, and all of the seraphs would have been born after that technique was discovered.

Then again, the Hyakuya must have gotten the gene from somewhere. I doubt they made it appear out of thin air. It could be possible that some people had it before.

I wonder if the Horsemen have the seraph gene, too. Fortunately, the first LN is published in English next month, so maybe it will reveal something. I don't think Guren encounters his first Horseman until a later volume, though.