"Dark Demon God Boo" (暗黒魔神ブウ Ankoku Majin Bū) is the fifth chapter of Super Dragon Ball Heroes: Dark Demon Realm Mission!.
Xeno Goku faces off against Xeno Majin Buu having now merged with the Three-Star Dark Dragon Ball in battle. As the Dark Empire Forces surround them on all sides, Demon God Dabura descends onto the battlefield and soon attacks Xeno Majin Buu with his objective to steal the dark Dragon Ball from him. Dabura notes that the version of him from this history has been taken care of. Withdrawing a sword he slices Xeno Majin Buu in half before turning his attention towards Xeno Goku who rushes in to attack him. However whilst Dabura is preoccupied with Xeno Goku, Xeno Majin Buu takes Dabura by surprise and absorbs him, transforming him into the more powerful Dark Demon God Buu.
The Dark Empire Forces rush at the newly formed Xeno Majin Buu but they along with their ships are quickly eradicated by him before he turns his attention on Xeno Goku. He attacks Xeno Goku and appears to have the upper hand. Chronoa appears on the battlefield having transported both Xeno Trunks and Xeno Vegeta along following their battle with Xeno Cell and Gravy. Xeno Trunks intercepts a blow from Xeno Majin Buu that was meant for Xeno Goku then turns Super Saiyan in an attempt to buy the others some time. Chronoa removes her Potara earrings and gives them to Xeno Goku and the reluctant Xeno Vegeta which transforms them into Xeno Vegito.
Xeno Vegito immediately steps in between the battle involving Xeno Majin Buu and Xeno Trunks. Xeno Vegito and the empowered Xeno Majin Buu begin fighting where they prove to be a match for each other, exchanging blows on both sides. Xeno Vegito fires his Spirit Sword technique directly at Xeno Majin Buu but before it reaches him the attack is blocked by the sudden appearance of Chamel.
Meanwhile, in another Dimension, Xeno Turles who has merged with the Four-Star Dark Dragon Ball encounters Salsa who has shown up alongside Mechikabura and the Dark-Masked King in order to recover his Dark Dragon Ball.
- Xeno Goku
- Xeno Majin Buu
- Xeno Trunks
- Xeno Vegeta
- Xeno Turles
- Dark-Masked King
- Xeno Vegito
- Xeno Goku vs. Xeno Majin Buu
- Dabura (Demon God) vs. Xeno Majin Buu
- Xeno Goku vs. Dabura (Demon God)
- Xeno Goku vs. Xeno Majin Buu (Dark Demon God Buu)
- Xeno Trunks (Base/Super Saiyan) vs. Xeno Majin Buu (Dark Demon God Buu)
- Xeno Vegito vs. Xeno Majin Buu (Dark Demon God)
Game and Manga differences
- While the beginning of the game has Dabura face Buu, the manga instead has Xeno Goku who facing off against Buu.
- Chamel comes much later in the manga, albeit without with team.
- The entire fight between Vegito and Buu is never shown in the game.
- The introduction of Xeno Turles is much sooner than in the game, with Mechikabura and his group there to retrieve the Dark Dragon Ball in his chest.
- This chapter and it's events are loosely based on the third Super Dragon Ball Heroes opening.