One of the biggest fan-favorite characters in Akira Toriyama's iconic Dragon Ball franchise is the formidable Vegeta. The prince of the doomed Saiyan race, Vegeta was originally introduced as a merciless conqueror, destroying and subjugating entire planets on behalf of the interstellar tyrant Frieza.
After being defeated by Goku and the Z Fighters, Vegeta eventually settled down on Earth as he trained to surpass Goku and become the mightiest Saiyan in the universe. This rivalry would lead him to embrace his own inner darkness years later and transform into the evil Majin Vegeta.
A decade after coming to Earth, Vegeta's bloody warrior ways had subsided somewhat. He had started an impromptu family with longtime Dragon Ball character Bulma, raising a young son named Trunks with her while constantly training himself to grow stronger. This sense of complacency bothered the Saiyan Prince, especially after the death of Goku fighting against Cell, seemingly robbing him of the chance to reclaim his perceived lost honor by defeating him in a rematch. This would change when Goku returned to Earth for a single day and the reunited rivals learned that an evil wizard named Babidi intended to unleash the monstrous Majin Buu.
Vegeta observed that those serving Babidi were brought under his control by dark magic. In return for their forced servitude, Babidi used his supernatural abilities to significantly boost their combat strength, turning a weaker fighter named Spovovich into one capable of flight and surviving fatal injuries. After realizing that Goku had surpassed his own strength once again by training in the afterlife, Vegeta secretly allowed Babidi to enter his mind and take control of him, triggering the transformation.
Babidi awakened the dormant evil inside Vegeta's heart, with the sinister Super Saiyan gleefully murdering innocents and seemingly liberated from the family man he had become. Able to sweep Gohan easily aside, Vegeta successfully goaded Goku into accepting a no-holds-barred rematch. Even with Goku's afterlife training and transformation into Super Saiyan 2, Vegeta could more than hold his own against his old rival in one of Dragon Ball Z's most thrilling fights. Later, Majin Vegeta fought one-on-one against the freed Majin Buu, holding the upper hand until Buu began fighting more seriously. Determined to make the same sort of heroic sacrifice Goku had made against Cell, Vegeta killed himself in a failed effort to destroy Buu.
In all of Dragon Ball Z, Majin Vegeta was the most powerful form taken on by the Saiyan Prince across the entire series. Vegeta's body was visibly paler and possessed with unnatural power while transformed by Babidi and, though Goku was holding back by refraining from transforming into a Super Saiyan 3, he was badly battered by Vegeta over the course of their rematch. Upon Vegeta's fiery, failed sacrifice to destroy Majin Buu, his resurrected form was cleansed of Babidi's power boost as he faced off against Buu for the fate of the universe.
Subsequent Dragon Ball series would introduce even more powerful forms for Vegeta but, within the perennially popular Dragon Ball Z, Vegeta's pinnacle of power was in his Majin form. Back to his unhinged evil ways and unnaturally boosted by dark magic, Vegeta's already impressive strength was significantly augmented as he faced off against Goku. While normally Vegeta would reject this more dishonorable means of gaining strength, Vegeta's desperation gave him access to a twisted blend of the supernatural and his training in a battle for the ages.