Purple and black

A Lone dragon, with unique abilities unsure of where he had come from searched for a new home. It was to bad he came across two powerful pony sisters who where fighting. He just wanted to help. Wanted to get them to stop fighting, because they were destroying everything. He had gone to the younger sister, had tried to talk to her, but he should have paid attention to his surroundings. He should have seen The blast coming he should have moved aside. Now 1000 years later he is freed along with Nightmare Moon, but surprisingly he isn't upset with Princess Celestia, but now that he's free he doesn't seem up to talking to Ponies, in fact he doesn't seem up to making new friends. Can the elements of Harmony teach this new dragon the meaning of friendship?