Before King Sombra was defeated he used a piece of his mane and dark magic to created the perfect Dragone Clone of himself just in case something were to happen to him and somehow. Sombragon was just an egg during that time and King Sombra somehow hid it in the Throne Room of the Crystal Empire and lost memory of it. After King Sombra came back and reformed he started having visions about what would happen if the egg hatched and went to the Crystal Empire to see if everything is okay. He found the egg under the thrones and had no idea why he put it there. King Sombra was put in charge of the egg and hoped to reform the creature when it hatches. While the Sombragon was an egg he created Nightmare Moon II to cause fear and chaos so the Sombragon could strong enough to hatch. When Nightmare Moon II did what she did the Sombragon had no further use for the Alicorn clone and stripped her of her memories. When he hatched King Sombra remembered why he put the egg in the Throne Room and the purpose he created the Sombragon. The Sombragon was more ruthless and more powerful than King Sombra and got the upper claw when he fought his creator in front of the Crystal Empire. When Luna was hurt King Sombra snapped and turned into a beast and continued fighting the Sombragon until they were both exhausted. Before the Sombragon could finish King Sombra off King Sombra held on to the Sombragon and told the Mane Six to use the Elements of Harmony, turning the evil dragon to stone. King Sombra, in cold blood, reduced the Dragon Clone to rubble before turning back to normal and turning to stone because of the darkness he used. The Crystal Heart made the tears everyone was shedding magical and the tears revived King Sombra as a Crystal Pony. The Crystal Heart also revived the Sombragon as a colt named Umbra, giving him a second chance.