so let me get this straight.
The Supereme Hyullas have beeen having incest babies to increase their power, but at the same time its corroded the bloodline to such a point that it will remove the Hyulla powers from all Hyullas.
But it got harder to make children between S Hyullas.
but because MC has half Supreme Hyulla Blood and Nam Blood, he can have child with her, but the genetic diversity will not increase the power of the bloodline but completely wipe out the power of the Hyullas.
That doesnt really make much sense.