I don’t see how it does. It just declares victory by definition and closes up shop. Why is having the character he has necessary? Why does necessity translate to goodness? How do we know that his necessary character is good unless we have a standard by which to judge?
This would seem to lead either to changing our understanding of God’s character so as to decide he isn’t good (if we accept our own standard) or deciding that our standard is wrong and adopting his. But the second alternative would seem to lead us to approval of genocide. Does that seem good to you, and if it doesn’t are you willing to change your idea of goodness to include genocide?
I’m not talking about merely commanding genocide. My reference is the flood, in which he performs the genocide himself. Now why should not being a human being make genocide right?
Now that’s a viable alternative. Do you reject the Flood as history, then?
I believe I see.
I don’t actually see how your third alternative could work. There’s no space between arbitrariness and conformity with a standard. (Well, actually, there is: the subjective human moral standard; but that doesn’t help God.) You can’t make God’s character objectively good just by saying so. This is no escape from Euthyphro.