Bottro

"I hate you ! " — Android 21 to her Mother, Pan

Bottro or Android 21 appears in Dragon Ball Z: Shenron Rises.

Pre-Evil Reborn
Before the events of Evil Reborn, Bottro was simply a child being raised by Pan and Giru

Shenron Rises
Bottro, being a Cyborg, could easily have her thoughts manipulated and she did by Cell causing her to think that she is called Android 21 and that she must kill the good guys.

Android 21, Cell and the Gods of Destruction (excluding Bills) succeed in killing Android 21's so called enemies.