SDBH: Dark Empire Saga

Towa, a scientist from the Demon Realm, and Mira, an artificial being created by Towa, had altered history countless times for the purpose of collecting energy produced by the resulting battles. Their goal: use the collected energy to unleash the Demon Realm and revive its ruler, Mechikabura!

Towa freed Mechikabura, who was sealed in the Demon Realm. Wishing to restore Mechikabura to his prime, Towa brainwashed Dende, who then created the Dark Dragon Balls. In order to collect the Dark Dragon Balls, the Dark Empire traveled through time and began their invasion!

With all the Dark Dragon Balls in his possession at last, Mechikabura finally regained his full power. In order to counter him, the Supreme Kai of Time unleashed the "Time Labyrinth" and succeeded in sealing Mechikabura along with herself. However, the battle was far from over. Mechikabura still lurked in the dark, seeking his own resurrection and that of the Demon Realm...

With the help of his fated enemy Demigra and Demigra's secretary Robelu, Trunks acquired the Key Sword that could open the hell gates to the Demon Realm. Using the Key Sword's darkness-purging power, he managed to rescue the Supreme Kai of Time. All that was left to do was to defeat Mechikabura. Trunks, who has transformed into the legendary Super Saiyan God, versus Mechikabura, who has unleashed the power of time... The final battle of "time" between light and darkness begins!

Mechikabura's ambition was thwarted thanks to the efforts of Trunks and the others. With Tokitoki's power, time was corrected and the history that had been absorbed by Mechikabura was restored...