Janemba

Janemba is the main antagonist of movie #12, Dragon Ball Z: Fusion Reborn. He is a demon of pure evil and great power created when a teenage ogre, also known as the Saike Demon, who was responsible for watching the spirit cleanser in Hell, slacked off, and the cleanser exploded as a result of the ogre's carelessness. The evil formed around him to create a giant, yellow, and childlike being that turns Hell into his own paradise. Goku and Pikkon are interrupted from their match in the Other World Tournament to fight Janemba, Pikkon being left behind to free King Yemma from the barrier that Janemba created around his castle. Eventually, Janemba's weaker first form is destroyed by Goku, forcing a transformation to his second state, which enables him to overcome Goku. Vegeta appears and assists Goku, but both of them are not strong enough to defeat Janemba. The two eventually defeat Janemba by fusing into Gogeta, who destroys Janemba by purifying his pure evil energy and turning him back into the Saike Demon.


About Janemba Transformations

1.Saike Demon
The Saike Demon is a tank-boy, who works for King Yemma in Hell, on the Soul Cleansing Machine. This ogre goofs off on the job by listening to heavy metal music on a handheld, and the Spirit Laundry Machine overloads and breaks, covering him in thousands of years of evil energy and mutating him into Janemba.

2. Janemba
His first form (called Janempa in the FUNimation Dub) is chubby and extremely large. Janemba's intelligence also seems quite limited; the only word he knows how to say is his own name. His attacks involve things such as creating miniature versions of himself and of Goku, creating dimensional portals, and shooting ki blasts from the four holes on his belly. Janempa also seems to be playful and not really trying, much like Majin Buu, which is used as a reference by Goku ("You should feel proud of yourself only Majin Buu has pushed me this far"). Even in this base form, he, for the most part, managed to beat around Goku in both his normal and Super Saiyan form. After causing immense destruction around him, he finally forces Goku to transform into his Super Saiyan 3 form. At this stage, Goku easily overpowers Janempa, smashing his head into his body. After being defeated, Janempa transforms.

3. Super Janemba
 Janemba's second form (known as "Janemba Final Form" in Budokai Tenkaichi 2 and "Super Janemba" in Budokai Tenkaichi 3) is much more powerful than his first and is more structured for fighting. Janemba reaches this stage after his head is caved into his torso from Goku's punch, he then proceeds to compress himself into a smaller space, resulting in this new form. This form is able to use a deconstruction/reconstruction teleportation known as the Bunkai Teleport, portals with which he can attack through, stretch his arm at lengths, turning objects into deadly weapons, project his opponents' own Ki Blasts back at them through portals.
He wields a powerful sword capable of shooting unblockable ki out in strikes, though Vegeta destroyed this sword. In this more powerful form, Janemba overpowers Goku even when he is at Super Saiyan 3. Even after Vegeta shows up and helps Goku fight him, Janemba is still able to effortlessly overpower the both of them. However, once they successfully fuse to form Gogeta, Janemba is unable to phase them with even his most powerful punches. In a short time, Janemba is defeated effortlessly by Gogeta with the Stardust Breaker, restoring the Saike Demon to his original state.

Information from:
http://dragonball.wikia.com/
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http://tekilazo.deviantart.com/