While the Imperfect Cell Saga officially brought one of Dragon Ball Z's most memorable villains to the forefront, it was the subsequent Perfect Cell Saga that truly made the antagonist a threat to be remembered. Running through chapters 180-194 of Akira Toriyama's manga series, and episodes 153-165 of the anime adaptation, the storyline saw Cell complete his plan to absorb Android 18 and reach his final form. Meanwhile, Goku and the Z Fighters scrambled to find a way to ascend past the normal limits of Super Saiyan to meet the villain at his level.
Here are the biggest plot twists from the Perfect Cell Saga, the storyline that set up the final confrontation with the synthetic enemy that would haunt DBZ and the surviving Z Fighters for years.
Goku Returned in the Perfect Cell Saga
For much of the Android and Imperfect Cell Sagas, Goku was laid up and fighting for his life after contracting a rare heart virus. After taking medication provided by Future Trunks, Goku eventually recovered from the life-threatening disease, just in time to finally meet Cell.
With Piccolo and Tien at Cell's mercy after the villain absorbed Android 17 to reach his semi-perfect state, Goku arrived in the nick of time to save his friends. The moment gave Goku and Cell their first meeting, brief as it was, with Goku using Instant Transmission to retreat after quickly realizing he didn't stand a chance against his opponent at his current state.
Vegeta Unleashed His Final Flash Against Cell
After Cell absorbed 18 and reached his dreaded, perfect state, it was quickly clear to Vegeta that, even after a year of training in the Hyperbolic Time Chamber, he was completely outmatched. Growing increasingly frustrated and desperate, Vegeta dared Cell to take the brunt of his ultimate attack, a technique he perfected in the Hyperbolic Time Chamber known as the Final Flash.
Cell accepted Vegeta's challenge and, after taking a significant amount of time to charge up, Vegeta unleashed the full might of the Final Flash upon Cell. To everyone's surprise, the attack had the potential for extreme damage, forcing Cell to regenerate a lost limb before turning his attention back to Vegeta. Clearly the Saiyan Prince could still put some hustle behind that muscle.
Goku's Plan for Gohan
Although Gohan trained under his father Goku and Piccolo in preparation for the androids' arrival, Goku realized he had to take things up to the next level with his son. Entering the Hyperbolic Time Chamber after Future Trunks and Vegeta to train for a relative year over the course of a single day on the outside, Goku sought to not only make Gohan a Super Saiyan, only for the father and son to ascend beyond the transformation's limits.
Two surprises awaited Gohan inside the Hyperbolic Time Chamber: Goku quickly proved himself to be a stricter, more exacting martial arts mentor than Piccolo but also declared he intended for Gohan to exceed him, foreshadowing Gohan's bigger role in the coming showdown with Cell.
Trunks Is Stronger Than Vegeta
Vegeta always kept Future Trunks at a distance, even after learning the Super Saiyan was his son from an alternate timeline. That led Trunks to prepare largely by himself while he and Vegeta trained in the Hyperbolic Time Chamber, where each achieved the mid-grade transformation of Ultra Super Saiyan.
However, the big twist came that Future Trunks had continued training in the form more than his father had, resulting in an even bulkier and stronger Ultra Super Saiyan transformation. Waiting until Vegeta was knocked unconscious against Perfect Cell to avoid wounding his pride, Future Trunks unveiled the new transformation against Cell, only to discover that, while physically stronger than his opponent, he sacrificed his speed, leaving himself vulnerable.
Vegeta Allows Cell to Become Perfect
The biggest twist in the Perfect Cell Saga arrived when Cell was allowed to reach his perfect state in the first place, with Vegeta agreeing to offer the chance for Cell to absorb Android 18. Appealing to Vegeta's ego, Cell was convinced his perfect form was stronger than Vegeta's new Ultra Super Saiyan transformation. To test his bluff, Vegeta agreed to stand down and allow Cell to track his quarry.
What's even more surprising was the lengths Vegeta went in order to allow Cell to reach his perfect form, going as far to fight his son. That not only made Vegeta complicit in Cell achieving his goal but also becoming something of an active participant in allowing the villain succeed in his master plan.