The unknown Cell is the fourth chapter of Super Dragon Ball Heroes: Dark Demon Realm Mission.
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 numerous beings and a spaceship surrounding them.
- Cell-X vs Gravy
- Vegeks vs. Gravy
- Vegeks and Gravy vs. Cell-X
- Xeno Goku vs. Kid Buu
- Cell-X's death resembles the one he had at the hands of Gohan back in the Cell Games.