Sooo... I had Ethelwen protect the dragon eggs with one of his Advent abilities, which was enough to create a temporary pause. The diamond will stay in place after he falls unconscious and the Advent ends, but I'm sure a powerful magic being such as the Ghoul Sage has plenty of ways to get through diamond. If nothing else, the construct could completely uproot the whole diamond shell. Whatever you please. Since, I'm pretty sure the Ghoul Sage has to get the eggs. Not that I wouldn't be remarkably pleased if he did manage to protect them, but I don't think that is an option.