Dragon Ball Kai: Doragon bôru kai - Season 3 Episode 25

Cell continues to destroy islands until only one remains, the one on which Androids #16 and #18 are hiding. Before he can launch his attack, Vegeta and Trunks arrive as Super Saiyans. After some taunting, Vegeta initiates a transformation that produces a form beyond that of Super Saiyan – evidenced by increased muscle size and an intense golden aura. As an Ascended Super Saiyan, Vegeta makes easy work of Cell while Trunks watches from the sidelines. Meanwhile, Goku and Gohan begin their training in the Hyperbolic Time Chamber, where Goku states that he will not only make Gohan a Super Saiyan, but that he will make Gohan stronger than even himself.