[ That is certainly a lot less ambiguous wording than he'd hoped. Still, nothing says that Yato can't change. Ratio does not make it a habit to believe in Permanence, despite its existence as a Path. Even as a concept, its interpretation is quite flexible. ]

Even if there is no precedent, it does not mean you cannot change. Consider the difference between yourself then and now. If you truly embodied the desire to destroy humanity, you would have the connections and friendships you have now?

[ Not to mention, Hiyori probably wouldn't have promised to marry him. ]

You are also quite the creative individual. The desire to create quite different from the wish that gave you existence. Is that not proof that you are multi-faceted, just like any other?

[ Perhaps what Yato really needs is a change in perspective. He is convinced he can't change because he's a god and was born from a wish for destruction. But is it really the case that either of those factors play a role in what he is? ]

The debate between nature versus nurture has always been prominent in the study of sapient development, and I believe gods are not an exception. We only lack the data to prove it. Why not be the first one to disprove the null hypothesis?