Protection.

To protect.

One must serve the other, at all times. But what would happen if they split apart? What would happen if the entire world wanted one dead?

Then the entire world must be killed.

With this mindset, Rayne travels through Avalon. His smile had been ground down into non-existence. His eyes were lifeless. He had failed, hadn't he?

But, if at first you don't succeed... Restart.