The movie was better than I thought it would be.
Although I was a bit disappointed when i couldn't hear one word the large lion turtle said.
Since some people never heard it ...
At first when anng first finds him he says
"The true mind can weather all the lies and illusions without being lost. The true heart can touch the poison of hatred without being harmed. Since beginningless time, darkness thrives in the void, but always yields to purifying light"
then, when taking the Phoenix King's Firebending, he says
"In the era before the Avatar, we bent not the elements, but the energy within ourselves. To bend another's energy, your own spirit must be unbendable, or you will be corrupted and destroyed."
i think....so really the lion-turtle showed him how to energybend..