Dark Empire Saga is the second original story arc in Dragon Ball Heroes, beginning with the upgrade to Super Dragon Ball Heroes. It was later adapted into the second saga of Super Dragon Ball Heroes: Dark Demon Realm Mission!. It is preceded by the Dark Demon Realm Saga.
It is composed of several sub-stories:
Demon God Towa Saga
Cell X Saga
Demon God Buu Saga
Mechikabura's Descent Saga
Battle in Hell Saga
Towa uses energy stolen from strong people in order to revive her grandfather Mechikabura, however his body is old and he cannot move well. Towa tells him to use the Dark Dragon Balls to wish for youth so that he can take revenge on Chronoa, however the Dragon Balls scatter. Mechikabura notices one of them as it heads away, crossing space-time. Towa decides to go and get it but Mechikabura tells her to wait, deciding to grant her Demon God powers first.
It is soon apparent that a Dark Dragon Ball ended up on Namek in Age 762 (during the climax of the Battle of Namek). The ball having fused with the tyrant Frieza, empowering him to the point that he could overwhelm the newly transformed Super Saiyan Goku - even without using his 100% Full Power. The Time Patrol realize that this is altering history for the worst, and so Future Trunks and Xeno Goku head back to deal with the problem. Goku teams up with his past self and the two attack the now full power Frieza together, as Frieza holds the two Kamehameha back Future Trunks quickly slices him in half and he loses the Dark Dragon Ball, restoring history to normal as Super Saiyan Goku defeats the non-Dark Dragon Ball Frieza.
However, Demon God Towa manages to collect the Dark Dragon Ball - though Mira is killed by Future Trunks during the process - and brings it back to the Demon Realm with her, where she meets Mechikabura, who reveals that he has summoned more Demon Gods to aid in the search for the Dark Dragon Balls.
Chronoa discovers two changes in history and decides to split into two groups, she goes with Goku, and Future Trunks goes with a new helper - who turns out to be Vegeta. Vegeta tells Future Trunks that he will prove he is the strongest, not Goku. Vegeta wants to get going immediately, but Chronoa tells him that they all must pose first, Vegeta ignores and tells her that they should just get going.
Vegeta and Future Trunks arrive back in time, and Vegeta gives Future Trunks a device from Bulma that can locate the Dark Dragon Balls. The device leads them to the Cell Games arena, where they see the Z Fighters defeated by Cell, who has a Dark Dragon Ball. Vegeta easily beats down Cell and then destroys most of his body with a Final Flash, shocking Future Trunks with his strength. Vegeta prepares to finish Cell but is suddenly attacked by Demon God Gravy before he has the chance. Future Trunks catches him as he is sent flying and then places the Potara Earrings he obtained from Chronoa onto himself and the unconscious Vegeta, fusing the two into Vegeks. At the same time Gravy and Putine discuss how great their Demon God power is.
Vegeks suddenly appears, striking Gravy and announcing his identity, Gravy attempts to attack again but he is easily knocked down by Vegeks, angering him. Putine states that they must take them down, as they may get in the way in the future. However both parties are surprised as Cell begins to undergo a dark evolution.
Cell using the power of dark evolution transforms into Cell-X, a hulking giant of a being with multiple Spider-like legs that dwarves Vegeks in size. Whilst Vegeks is focused on Cell-X, Gravy takes the opportunity to hit Vegeks from behind, knocking him to the ground. Happy with catching Vegeks off guard, he too is then caught from behind by an attack from Cell-X who swiped him to the ground, Vegeks having quickly recovered, suddenly attacks Gravy and they battle briefly before Vegeks is grabbed by Cell-X and both he and Gravy are crushed as the weight of Cell-X comes crashing down on them both.
With both injured and annoyed at Cell-X getting in their way of their battle, they briefly put aside their fight and attack him in unison with the resulting attack wiping out Cell-X for good. Suddenly Vegeks diffuses leaving Vegeta and Trunks separated once again. As Gravy goes in for the finish on the two Saiyans they are suddenly teleported away by Chronoa's magic as Gravy wonders where they went.
Meanwhile a battered and bruised Goku stands off against Kid Buu with the Dark Empire forces surrounding them.
Plot (video game)
Demon God Towa
In the first game opening, Towa and her army bow to the revived Mechikabura as the Dark Dragon Balls are shown scattering. Future Trunks along with Beat and Note head back to Age 762 in order to prevent Frieza - who had merged with the One-Star Dark Dragon Ball - from killing Goku and manages to stop Frieza in time, causing him to lose the Dark Dragon Ball. However before they can get it, it is taken by Demon God Towa, who had come to obtain the Dark Dragon Ball, she then attacks the group with a giant energy ball. However Chronoa arrives and deflects the attack, having brought Xeno Goku and Xeno Vegeta along with her. Due to Towa's great Demon God power, Chronoa gives the Potara to Future Trunks and Vegeta, who fuse into Vegeks.
In the related PV trailer, Demon God Towa invades Earth with her army. After decimating the surrounding area, she encounters the Time Patrol and their allies, and sends her forces to face them. Future Trunks, Goten, Gohan, Vegeta and even Bulma deal with the many soldiers, while Goku and Beat face off against Towa, the two attack with a combined Kamehameha attack to no avail as Towa easily deflects it with her staff.
After defecting the attack, Towa's confidence fades as she notices Frieza - who has merged with the One-Star Dark Dragon Ball - arrives with Zarbon and Dodoria and she flees. The Time Patrol then prepare to engage the empowered Frieza in combat once more.
In the second game opening, Cell infused with the Two-Star Dark Dragon Ball defeats Super Saiyan 2 Gohan at the Cell Games. As he is about to go finish him off he is attacked by Gravy. He attempts to retrieve the Dark Dragon Ball from Cell but he is stopped by the appearance of Xeno Goku who appears along with Future Trunks, Beat and Note who soon attack Gravy but are easily knocked aside. As a result Goku transforms into a Super Saiyan 3 and easily defeats Gravy. Putine appears and uses her powers to empower Cell who transforms into Cell-X. Chronoa uses her power to send Bardock to travel back to the others to help out.
Demon God Buu
In the third game opening, Demon God Dabura easily takes down Kid Buu who has merged with the Three-Star Dark Dragon Ball, as he attempts to steal the ball he is stopped by the sudden appearance of the Time Patrol. Soon afterward Chamel along with two of his comrades show up and attack the Time Patrol. Distracted, Kid Buu absorbs Dabura, becoming Demon God Buu. After Goku and Vegeta realise that they are being overwhelmed by the Dark Empire's forces, they then fuse into Vegito via Chronoa's Potara earrings in order to fight back.
In the related PV trailer, Demon God Dabura is shown commanding his soldiers in the Demon Realm. Elsewhere Kid Buu now merged with the Three-Star Dark Dragon Ball, appears on Earth and the Time Patrol consisting of Goku, Vegeta, Future Trunks, Gohan, Goten and Beat show up to stop him. However they prove to be powerless against him leaving no choice but for Goku and Vegeta to fuse to become Vegito. Suddenly the Dark Empires forces also arrive on Earth with Demon God Dabura at the helm, they find themselves assisted by a mysterious warrior named Chamel; who attacks the forced and confronts Dabura in battle. Kid Buu then engages in combat with the Time Patrol once more before absorbing Dabura whilst caught unaware, transforming himself into Demon God Buu.
In the fourth game opening, with the Tree of Might in the background, Turles now merged with the Four-Star Dark Dragon Ball battles the Time Breaker member, the Dark-Masked King who he is evenly matched with. The Time Patrol consisting of Goku, Vegeta and Beat soon show up as does the Demon God Salsa who stands in their way. Beat attacks Salsa but is quickly knocked aside causing Vegeta to rush in for the attack next. The Dark Empire forces arrive on the battlefield as the Dark-Masked King takes the Dark Dragon Ball from Turles as he, along with Salsa rejoin Merchikabura on the top of his ship. Mechikabura uses his staff to create an energy blast to attack the Time Patrol with but Future Trunks shows up and transforms into a Super Saiyan 3 before confronting his enemies.
In the related PV trailer, Turles now merged with the Four-Star Dark Dragon Ball eats a piece of a fruit from the Tree of Might as he prepares to face Goku, Vegeta, Future Trunks and Beat in battle. They battle briefly until the the Dark Empire forces appear on the battlefield consisting of Mechikabura along with Demon God Salsa and the Dark-Masked King in order to retrieve the Four-Star Dark Dragon Ball from Turles. Turles attacks the Dark-Masked King who effortlessly bats him aside, Vegeta chooses to fight him alone and the others fly off to attack the remaining enemies with Salsa engaging in battle with Futre Trunks. Goku and Beat continue ahead to attack Mechikabura but are easily knocked away from one of his barrier attacks. Away from battle, Chamel approaches the fallen Turles and further empowers him.
Battle in Hell
In the fifth game opening, Time Patrollers, Goku, Vegeta and Beat are in Hell confronting the Demon God Shroom who showed up in Hell to acquire the Five-Star Dark Dragon Ball that has merged with Janemba but they appear to be struggling. Janemba gains more power from the ball and undergoes a transformation, he immediately attacks Shroom and quickly knocks him away before turning his attention to the others. Beat attacks Janemba but is also quickly knocked away, Goku and fuse into Super Saiyan Gogeta and rushes into battle with Janemba.
- Goku (Super Saiyan) vs. Frieza (Dark Evolution)
- Goku (Super Saiyan), Future Trunks and Xeno Goku vs. Frieza (Dark Evolution)
- Future Trunks vs. Towa and Mira
- Xeno Vegeta vs. Perfect Cell
- Xeno Vegeta vs. Gravy
- Vegeks vs. Gravy
- Cell-X vs Gravy
- Vegeks vs. Gravy
- Vegeks and Gravy vs. Cell-X
- Xeno Goku vs. Kid Buu
|2||"Dark Dragon Ball"|
|4||"The unknown Cell"|
|5||"Dark Demon God Boo"|
- The video game openings and the accompanying PV game trailers show events that are similar but not exactly the same.