The evil 21 leaves, along with her good counterpart, 18, and 17 resolving to cease her in memory of their fallen friend, Android sixteen. As the game progresses, 17 notices one thing strange about the new android, who was continually groaning and screaming, at one level 17 even saying he disliked her tone. However, when discovering Krillin, who was making an attempt to rescue 18, 21 finally snapped and advised about “eating” him which shocked 17. Luckily, the group managed to subdue Krillin and 21, with 17 having to maneuver Krillin’s body somewhere. After this incident, 17 and 18 demand an explanation from 16 and return to 21’s lab, the place it is revealed by 16 that Android 21 was a human converted right into a Bio-Android from the cells of varied fighters and scientists.
16 states they deliberate to use the soul hyperlink system developed by Dr. Gero to suppress the evil 21. Android 21 recreated 16 because of him being designed after her human son and would have lived peacefully with him had it not been for her cravings and growing evil persona. Goku’s last wish of Shenron after the battle with Syn Shenron restored the lives of those who didn’t need to die between the Super 17 and the Shadow Dragon Sagas, together with Android 17.
Pan’s ploy to have Gero convey 17 to a halt is ruined when Dr. Myuu reveals his programming positioned him in full management of the tremendous android, and so Super 17 kills Dr. Gero, for the second time. Piccolo and Dende create a gateway between Hell and Earth, permitting Goku to escape and confront Super 17, earlier than some other Z Fighters could be killed.
However a few of the cells (implied to be those of Kid Buu as his clones share the unique’s character) went uncontrolled causing Android 21 to develop cravings to show people into meals to consume and take up their power like Cell and Majin Buu. This triggered 21 to develop an evil split personality which is vying for management of Android 21’s physique.
As a result, 17, 18, and Good 21 join forces with the Z Fighters to combat 21 and the clones which she begins feeding on to fulfill her rising starvation. The Good 21 ultimately sacrifices herself to make sure her evil counterpart each are destroyed by Goku’s Spirit Bomb, to prevent herself from being ultimately being overcome by her cravings and turning on her newfound pals as she had with 16. When Goku tells his friends not to fear they are afraid he plans to revive 21 with the Dragon Balls but he notes that might fly in the face of 21’s sacrifice and that he instead plans to ask King Yemma reincarnate 21’s soul like he had done beforehand with Kid Buu’s. Wanting to guard her fellow Androids, 21 transforms right into a blue-eyed model of her true type with the help the soul hyperlink.
She manages to defeat Cell, however her cravings and evil persona take control and she or he destroys 16 when he tries to cease her from eating Cell. They manage to assist 21 come to her senses and overwhelmed with grief over having killed sixteen, Android 21 splits into Android 21 (Good) and Android 21 (Evil). The evil 21 inherits most of 21’s power and eagerly consumes Cell inflicting her pores and skin to change colour and gain patches on her skin just like Cell’s spots.