4x31 - Dragon Ball Z: Dragon Box

Not even a blast from Cell at full power is able to leave so much as a scratch on Super Vegeta. As Trunks, Kuririn, No. 16 and No. 18 look on, Vegeta backs Cell into a corner. As the gap between Vegeta and Cell becomes evident, Vegeta begins to think there is no worth in killing him. But then, Cell challenges him with a perilous enticement: "If only I could become my perfect form!"