Tharollin, picking up and using the dry bones of Lucifer, fought with the thousands skeletons heading his way.
It took him many, so many days to successfully take all of them down.
The skeletons scattered and couldn't raise to join themselves as they did before, he had used the bones of Lucifer on them, weakening them.
At last, he has the bones in his hands. He started going back to the way he had come before. He couldn't wait to see Avonmora and ask for her forgiveness.
His huge black wings came out from his back and he flew upwards, since he now has the bones of Lucifer with him, going out of the Gate of Darkness will be easier. Unlike when he was coming to look for the bones which took him a thousand years before he landed.
He came out and turned into a dark smoke which enables him to pass through the mouth of the Gate of Darkness which hasn't been closed yet, going back to his human form.
He turned to look at gate and smiled.
Finally he was outside.