Starchaser: The Legend of Orin

In the future on a planet named Trinia, human slaves have lived underground for millennia mining crystals for a "god" named Zygon and his robot minions. One day Orin, a young miner, finds a jeweled sword embedded in the rocks. Hopps, grandfather of Orin's girlfriend Elan, recognizes the sword and gives his life to save Orin and keep the sword a secret. When Orin later takes the sword into his hands, it ascends into the air and buries itself in the cavern's floor. A projection of an old man appears from the blade, telling those present that above the caverns is a "magnificent universe" that the people may find. The blade then disappears, leaving only the hilt.