The answer depend on this: how did Nergal vote? This knowing that in the western pantheon "yes" won...

If Nergal voted yes probably Hel knows this, and in this case Greg could simply tell Malak the truth and then going to the Godsmoot is easy; and without the Order (that has no way to know what is happening) the world simply goes Ka-Boom.

If Nergal voted no, Hel may not trust Nergal enough to tell the truth and risk everything on Nergal's sense of democracy. But Greg would tell Malak another truth: the fact that he wants to go north to the dwarven land to get revenge. This is something Malak would understand. But if he doesn't understand, and tell Greg to try to enjoy his new (un)life, Greg is still a high rated guest of the Empire, so I bet that a smart vampire like him can get his hand on some kind of teleportation device. Or some other kind of vehicle. He is powerfull enough to escape Malak and probably Malak wouldn't be willing to follow him, and even if he would, maybe he couldn't as Greg is smart and strong.
Then Greg goes north, votes and as the Order can't be there, the world goes Ka-Boom (again).