I don't know. I think that if a Humanoid is blooded, it's most likely that
he has the blood of Azrai. Not just a 30% chance.

As the story goes, when all the gods died, the people on the battlefield
acquired the energy, not randomly, but based on where they were during the
battle. I've always pictured the gods were floating overhead, kind of
exploding, and their blood kind of rained down on the troops. And so, most
the evil people got Azrai's blood, and the good people got the blood of the
various nice gods.

Let me draw a diagram (the /|\ is the rain of blood from the gods)

Nice Gods Azrai
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